Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content
Scientific Data Documentation
Access To Care File, 1996
DSN:  CC37.NHIS96.ACCESSX



              1996 National Health Interview Survey (NHIS)
                Access to Care Final Public Use Data File


 1.   The 1996 National Health Interview Survey (NHIS) Access data
      file contains a variety of data items addressing access to
      health care services. These data items are identical to the
      1995 Access data items.

      As a result of a Federal government furlough, two weeks of
      data collection were omitted in January of 1996. In addition,
      in order to test the changing NHIS core questionnaire, for
      much of the year the sample was split between the old (paper)
      and the new (computerized) versions of the core questionnaire.
      This data file includes only data obtained from the paper
      version of the NHIS questionnaire. The sample size is considerably
      smaller than in the previous year (63,402 vs. 102,467).
      The weights have been adjusted for these factors to produce
      national estimates, however, there may be a minor seasonal
      effect which is not corrected by the weighting.

 2.   The 1996 Access supplement was administered for the full year
      (except as mentioned above) in all of the NHIS sample households
      interviewed with the old paper core using three-quarters
      of the sample households from January-June and one-half of the
      sample households from July-December. Information was
      collected from a household respondent about all family members
      who participated in the NHIS.

      The 1996 Access file is structured in the following way:

      a.   The NHIS person record from the core questionnaire
           (locations 1-335)
      b.   The weight fields (locations 201-236)
      c.   Fields needed for calculating variances (locations
           337-358)
      d.   Data from supplement (locations 401-439)

      Note: All data from the Access supplement have been shifted to
      start in location 401 in order to accommodate a longer public
      use person record required by the new sample design in 1995.

 3.   In 1996, two types of item non-response were identified:

      (1)  "Not ascertained" (codes 8, 98, or 998) includes blanks
           when there should have been a response or when an impos-
           sible code appeared and;
      (2)  Responses of "don't know" or "refused" when the question
           was asked (codes 9, 99 and 999).

 4.   The overall response rate for the 1996 Access was 90.0 per-
      cent. This response rate was calculated as follows:

           Household response rate from core of 93.8 percent multiplied
           by 95.9 percent who responded to the Access section yields
           an overall response rate of 90.0 percent.

      Dummy records were created for those with no response to the
      entire section (see file location 400).

 5.   Weights and variances:

      Since the NHIS uses a multistage sample design to represent
      the civilian non-institutionalized population of the United
      States, weights must be used to make accurate estimates based
      on data from the National Health Interview Survey.

      A set of weights are included on the 1996 file:

      The first weight listed below (i.e. the Final Basic Weight)
      will be used in most analyses of the Access data.

      The Final Basic Weight (location 219-227) is the equivalent of
      the Annual Final Basic Weight found on the NHIS Person Record
      of the Basic Health and Demographic component of the survey
      (i.e. the Core questionnaire). A national estimate of all
      person level variables can be made using this weight.

      This weight will be used in conjunction with Access data items
      in file locations 401-439.

      The Final Quarter Basic Weight before age-sex-race/ethnicity
      adjustment (loc. 172-177) is required by some software packages
      for variance estimation for surveys with complex sample
      designs.  This weight is also included on the file.

      As mentioned above, the sample design for the NHIS was changed
      for 1995. Data from 1995 and 1996 can be combined with data
      from previous years, however, variances for 1995 and 1996
      must be calculated separately from variances of previous
      years. In addition, because of the smaller sample size in
      1996, some of the design elements were combined for reasons of
      confidentiality. The exact changes are included in the explanation
      below.

      There are a number of computer programs that yield variance
      estimates for data based on complex sample surveys.  Some are
      based on replication approaches and others are based on Taylor
      linearization approaches. In addition to the Final Quarter
      Basic Weight before age-sex-race/ethnicity adjustment (which is
      the weight prior to post-stratification), included on the
      Access file is the substratum for variance estimation (loc.
      342-343), the secondary sampling unit (loc. 344-350), Panel 4
      (loc. 352), the variance PSU for 1996 (loc. 358), the
      collapsed variance stratum for 1996 (loc. 354-357), and the
      NSR Status variable for 1996 (loc. 353) to permit the analyst
      the capability of using such variance estimation procedures.
      These variables and weights are necessary for directly
      calculating sampling variances.

 6.   Estimating annual numbers of events or conditions

      a.   To reduce respondent error, the recall period for
           questions about some events is limited to two weeks.
           These events are: bed days and other restricted activity
           days, work loss and school loss days, and doctor visits.
           The two-week variables are found in locations 98-107 and
           120-121.  Estimates of the total number of occurrences of
           these events in the population can be derived as follows:

                Number of events x 26 (number of two-week
                periods in a year) x Final Basic Weight

                =    Total number of events occurring in the
                     population during the annual period,
                     i.e. 1996.

           Example:  Number of bed days (Loc. 100-101) x 26 x Final
           Basic Weight (Loc. 219-227) = total number of bed days
           reported for the population in 1996.

      b.   The recall period for acute incidence conditions is also
           two weeks and a national estimate of the total number of
           acute incidence conditions is calculated using the same
           procedures as for two-week events for the annual period.

                Number of acute incidence conditions x 26 x Final
                Basic Weight

                =    Total number of acute incidence conditions
                     occurring in the population during 1996.

           Note:  An acute incidence condition is an acute condition
           with onset during the two weeks preceding the date of
           interview.

      c.   The recall period for information on hospitalizations is
           12 months.  However, in calculating number of discharges
           (Locations 132-133, 137-138), only discharges occurring
           in the past 6 months are counted.  Therefore, the
           weighted estimates must be calculated as follows:

                Number of discharges x 2 x Final Basic Weight

                =    Total number of discharges occurring in the
                     population in 1996.

 7.   Calculation of rates for events and conditions:

      The number of events or conditions estimated for the
      population, as described in item 6, above, can be used as the
      basis for calculating rates of occurrence of these events (or
      conditions) per person and per 100 persons for the total U.S.
      population and for various population subgroups.

      Note:  Only rates can be estimated from these data.  The
      percent of the population experiencing a particular type of
      event during the data year cannot be estimated. (The percent
      of the population experiencing the event in the reporting
      period (i.e. two weeks or 6 months) can be estimated but is
      generally not meaningful.)

 8.   Data on hospital episodes and days, based on a 12-month recall
      are in locations 122-131.  The Final Basic Weight is used for
      calculating estimates of these events in the same way it is
      used for all other person-based variables.  These variables do
      permit estimating the percent of the population in this annual
      period experiencing a hospital episode in the past year and
      the percent of that population having a specified number of
      hospital days.

 9.   Guidelines for Citation of Data

      With the goal of mutual benefit, the National Center for
      Health Statistics (NCHS) requests that recipients of data
      files cooperate in certain actions related to their use.

      Any published material derived from the data should
      acknowledge NCHS as the original source.  The suggested
      citation to appear at the bottom of all tables is as follows:

           Source:  National Center for Health Statistics (1996)

      When cited in a bibliography, the suggested citation should
      read:

           National Center for Health Statistics (1998).  Data File
           Documentation, National Health Interview Survey of Access
           to Care, 1996 (machine readable data file and
           documentation), National Center for Health Statistics,
           Hyattsville, Maryland.

      The published material should also include a disclaimer that
      credits any analyses, interpretations, or conclusions reached
      to the author (recipient of the data file) and not to NCHS,
      which is responsible only for the initial data.  Consumers who
      wish to publish a technical description of the data should
      make a reasonable effort to insure that the description is not
      inconsistent with that published by NCHS.


                                  AC-1

               1996 NATIONAL HEALTH INTERVIEW SURVEY (NHIS)
                      ACCESS TO CARE PUBLIC USE FILE

                        Outline of Items and Codes

                              63,402 Records
 ______________________________________________________________________
  File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 1-2          -                        RECORD TYPE

                           63,402          70.  Access to Care Supplement
 ______________________________________________________________________

 3-4          HH-2                     PROCESSING YEAR

                           63,402      96.  1996
 ______________________________________________________________________

 5-14         Recode            -      HOUSEHOLD ID
 ______________________________________________________________________

 15-16        -                 -      PERSON NUMBER
 ______________________________________________________________________

 17-18        -                 -      BLANK (Record Serial Number on some
                                       other record types)
 ______________________________________________________________________

 19-20        -                        SAMPLING WEEK CODE
                                       (Numbered within quarter)

                            3,680          01.  Week 1
                            3,422          02.  Week 2
                            5,414          03.  Week 3
                            4,966          04.  Week 4
                            5,009          05.  Week 5
                            4,867          06.  Week 6
                            5,512          07.  Week 7
                            5,183          08.  Week 8
                            5,390          09.  Week 9
                            4,992          10.  Week 10
                            4,714          11.  Week 11
                            5,128          12.  Week 12
                            5,125          13.  Week 13
 ______________________________________________________________________

                                    AC-2

                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   21         Recode                   LATE INTERVIEW (OR LAST ATTEMPT)
                                       FLAG

                           36,891           0.   Interview not late
                           18,591           1.   One week late
                            6,372           2.   Two weeks late
                            1,548           3.   Unknown
 ______________________________________________________________________

 22-23        HH-11c,d                 TYPE OF LIVING QUARTERS:

                                       Housing Unit = (00-07)

                            1,234          00.   Housing unit; kind unknown
                           58,363          01.   House, apartment, flat
                               37          02.   HU in nontransient hotel,
                                                 motel, etc.
                                5          03.   HU-permanent in transient
                                                 hotel, motel, etc.
                               20          04.   HU in rooming house
                            3,072          05.   Mobile home or trailer with
                                                 no permanent room added
                              450          06.   Mobile home or trailer with one
                                                 or more permanent rooms added
                               51          07.   HU not specified above

                                       Other Unit = (08-13)

                               39          08.   Quarters not HU in rooming or
                                                 boarding house
                                3          09.   Unit not permanent in transient
                                                 hotel, motel, etc.
                               14          10.   Unoccupied site for mobile
                                                 home, trailer, or tent
                               90          11.   Student quarters in college
                                                 dormitory
                               24          12.   Other unit not specified above
                                0          13.   Other unit; kind unknown
 ______________________________________________________________________

   24         HH-12a                   HAS TELEPHONE

                           57,080           1.   Yes, phone number given
                            2,558           2.   Yes, no phone number given
                            3,099           3.   No
                              665           4.   Unknown
 ______________________________________________________________________

   25         A-1                      SEX

                           30,358           1.   Male
                           33,044           2.   Female
 ______________________________________________________________________

                                    AC-3

                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________
   26         -                        AGE IMPUTED FLAG

                           63,400          0.   Age known
                                2          1.   Age unknown, imputed
                                                as 34
 ______________________________________________________________________

 27-28        Person                   AGE
              Column
                              976         00.   Under 1 year
                           62,241      01-89.   Number of years
                              185         90.   90+ years old
 ______________________________________________________________________

   29         Recode                   AGE RECODE #1

                            4,918          1.  Under 5 years
                           13,210          2.  5-17 years
                            5,568          3.  18-24 years
                           19,974          4.  25-44 years
                           12,598          5.  45-64 years
                            2,213          6.  65-69 years
                            1,928          7.  70-74 years
                            2,993          8.  75 years and over
 ______________________________________________________________________

   30         Recode                   AGE RECODE #2

                            6,008          1.  Under 6 years
                           11,219          2.  6-16 years
                            6,469          3.  17-24 years
                            9,603          4.  25-34 years
                           10,371          5.  35-44 years
                            7,673          6.  45-54 years
                            4,925          7.  55-64 years
                            4,141          8.  65-74 years
                            2,993          9.  75 years and over
 ______________________________________________________________________

 31-32        Recode                   AGE RECODE #3

                            2,905      00-35.  Months
                           60,497         36.  Over 3 years old
 ______________________________________________________________________

   33         -                        MONTH OF BIRTH IMPUTED FLAG

                           60,272          0.  Month known
                            3,090          1.  Month unknown, '8' imputed
                               40          9.  Date of birth unknown
 ______________________________________________________________________

                                    AC-4

                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________
 34-39        A-3               -      MONTH AND YEAR OF BIRTH

 34-35                                 Month
                                          01.  January      08.  August
                                          02.  February     09.  September
                                          03.  March        10.  October
                                          04.  April        11.  November
                                          05.  May          12.  December
                                          06.  June         99.  Unknown
                                          07.  July

 36-39                                 Year of Birth
                              168           1905.  1905 and before
                           63,194      1906-1997.  1906-1997
                               40           9999.  Unknown
 ______________________________________________________________________

   40         Recode                   HISPANIC ORIGIN IMPUTED FLAG

                           62,712          0.   Hispanic origin known
                              690          1.   Hispanic origin imputed from
                                                reference person
 ______________________________________________________________________

 41-42        A-6                      MAIN RACIAL BACKGROUND* - Reported
                                       (see notation for locations 43-45)

                           46,996         01.   White
                            9,027         02.   Black/African American**
                              482         03.   Indian (American)
                              325         06.   Chinese
                              455         07.   Filipino
                              987         15.   Other API (includes Hawaiian,
                                                Korean, Vietnamese, Japanese,
                                                Asian Indian, Samoan, and
                                                Guamanian)
                            3,797         16.   Other race (includes Eskimo
                                                and Aleut)
                              181         17.   Multiple race
                            1,152         99.   Unknown
 _____________________________________________________________________
 *   Some categories may be too small to analyze separately and
     therefore may produce unreliable estimates; in addition, counts
     may not agree with those produced by the Census Bureau.

 **  For convenience, the category 'Black/African American' will be shown
     as 'Black' in all observed race or race recode locations throughout
     the documentation.


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 43-45        Recode                   RACE RECODES

   43                                  Recode 1*         Persons whose Main
                           51,962       1.  White        Racial Background
                            9,065       2.  Black        (location 41-42) was
                            2,375       3.  Other        "other" or "unknown"
                                                         were classified in
   44                                  Recode 2          the following recodes
                                                         by using the racial
                           51,962       1.  White        background observed
                           11,440       2.  Non-white    by the interviewer.
                                                         Use of these recodes
   45                                  Recode 3          is recommended for
                                                         estimating statistics
                            9,065       1.  Black        for the groups shown
                           54,337       2.  Non-black    here.
 ______________________________________________________________________

 46-47        A-5                      HISPANIC ORIGIN**

                               12      00.  Multiple Hispanic
                            1,387      01.  Puerto Rican
                              646      02.  Cuban
                            3,935      03.  Mexican-Mexicano
                            4,391      04.  Mexican-American
                               99      05.  Chicano
                            1,133      06.  Other Latin American
                            1,184      07.  Other Spanish
                              338      08.  Spanish, DK type
                              114      09.  Unknown if Spanish origin
                           50,163      10.  Not Spanish origin
 ______________________________________________________________________

   48         L-7                      MARITAL STATUS

                           14,293       0.  Under 14 years old
                           28,314       1.  Married - spouse in household
                              494       2.  Married - spouse not in household
                            3,022       3.  Widowed
                            3,475       4.  Divorced
                            1,102       5.  Separated
                           12,070       6.  Never married
                              632       7.  Unknown
 ______________________________________________________________________

  *This recode is used to define race in the Current Estimates tables.

 **If unknown, the family reference person code was imputed.  A flag
   indicating imputation is in loc. 40 and the relationship to reference
   person is in loc. 63.


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________
   49         L-1                      VETERAN STATUS

                           38,331          1.   Non-veteran
                            1,311          2.   WW I and WW II
                              800          3.   Korean War
                            1,715          4.   Vietnam veteran
                              810          5.   Post-Vietnam
                            1,070          6.   Other service
                              163          7.   Served in Armed Forces,
                                                unknown if war veteran
                            1,074          8.   Unknown if served in
                                                Armed Forces
                           18,128      Blank.   Under 18 years old
 ______________________________________________________________________

   50         L-1                      ACTIVE GUARD/RESERVE STATUS FOR
                                       PERSONS ON ACTIVE DUTY IN ARMED
                                       FORCES

                           38,331          0.   Non-veteran
                              363          1.   All service in Guard/Reserve
                              740          2.   Some service in Guard/Reserve
                               36          3.   Unknown if all service in
                                                Guard/Reserve
                            4,159          4.   No active service in Guard/
                                                Reserve
                            1,645          5.   Unknown if ever active member
                                                in Guard/Reserve or served
                                                in Armed Forces
                           18,128      Blank.   Under 18 years old
 ______________________________________________________________________

 51-52        L-2                      EDUCATION OF INDIVIDUAL - COMPLETED YEARS

                            2,628         00.  Never attended; kindergarten
                                               only
                           19,974      01-11.  Grades 1-11
                           16,207         12.  Grade 12

                                       College:

                            3,321         13.  1 year
                            4,433         14.  2 years
                            1,602         15.  3 years
                            5,424         16.  4 years
                            1,039         17.  5 years
                            2,762         18.  6 years or more
                            1,094         19.  Unknown
                            4,918      Blank.  Under 5 years old
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________
   53         Recode                   EDUCATION OF INDIVIDUAL

                            2,628          0.  None; kindergarten only
                           12,480          1.  1-8 years (elementary)
                            7,494          2.  9-11 years (high school)
                           16,207          3.  12 years (high school
                                               graduate)
                            9,356          4.  1-3 years (college)
                            5,424          5.  4 years (college graduate)
                            3,801          6.  5+ years (post-college)
                            1,094          7.  Unknown
                            4,918      Blank.  Under 5 years old
 ______________________________________________________________________

 54-55        -                        HIGHEST EDUCATION OF RESPONSIBLE
                                       ADULT FAMILY MEMBER (Detail)

                              151         00.  Never attended; kindergarten
                                               only
                            9,278      01-11.  Grades 1-11
                           20,685         12.  Grade 12

                                       College:

                            4,719         13.  1 year
                            7,364         14.  2 years
                            2,688         15.  3 years
                            9,589         16.  4 years
                            2,073         17.  5 years
                            6,048         18.  6 years or more
                              807         19.  Unknown
 ______________________________________________________________________

   56         Recode                   HIGHEST EDUCATION OF RESPONSIBLE
                                       ADULT FAMILY MEMBER

                              151         0.  None; kindergarten only
                            3,807         1.  1-8 years (elementary)
                            5,471         2.  9-11 years (high school)
                           20,685         3.  12 years (high school
                                              graduate)
                           14,771         4.  1-3 years (college)
                            9,589         5.  4 years (college graduate)
                            8,121         6.  5+ years (post-college)
                              807         7.  Unknown
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   57         L-8                      FAMILY INCOME $20,000 OR LESS

                           18,637         1.  Less than $20,000
                           42,177         2.  $20,000 or more
                            2,588         3.  Unknown
 ______________________________________________________________________

 58-59        L-8                      FAMILY INCOME

                              243        00.  Less than  $1,000
                              366        01.  $ 1,000 -  $1,999
                              319        02.    2,000 -   2,999
                              356        03.    3,000 -   3,999
                              433        04.    4,000 -   4,999
                              694        05.    5,000 -   5,999
                              695        06.    6,000 -   6,999
                              699        07.    7,000 -   7,999
                              701        08.    8,000 -   8,999
                              941        09.    9,000 -   9,999
                            1,132        10.   10,000 -  10,999
                              705        11.   11,000 -  11,999
                            1,304        12.   12,000 -  12,999
                              838        13.   13,000 -  13,999
                              828        14.   14,000 -  14,999
                            1,100        15.   15,000 -  15,999
                              777        16.   16,000 -  16,999
                              810        17.   17,000 -  17,999
                            1,042        18.   18,000 -  18,999
                            1,216        19.   19,000 -  19,999
                            4,786        20.   20,000 -  24,999
                            4,130        21.   25,000 -  29,999
                            4,150        22.   30,000 -  34,999
                            3,179        23.   35,000 -  39,999
                            3,180        24.   40,000 -  44,999
                            2,824        25.   45,000 -  49,999
                           15,137        26.  $50,000 and over
                           10,817        27.  Unknown
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   60         Recode                   FAMILY INCOME

                            1,717         0.  Under $5,000
                            1,389         1.  $ 5,000 - $ 6,999
                            2,341         2.    7,000 -   9,999
                            4,807         3.   10,000 -  14,999
                            4,945         4.   15,000 -  19,999
                            4,786         5.   20,000 -  24,999
                            8,280         6.   25,000 -  34,999
                            9,183         7.   35,000 -  49,999
                           15,137         8.  $50,000 or more
                           10,817         9.  Unknown
 ______________________________________________________________________

   61         Generated                NHIS POVERTY INDEX*

                           48,720         1.  At or above poverty threshold
                            8,572         2.  Below poverty threshold
                            6,110         3.  Unknown
 ______________________________________________________________________

 62-63                                 FAMILY RELATIONSHIP

   62       A-2                      Type of Family
                            6,440         &.  Primary individual
                              684         -.  Secondary individual
                           56,152         0.  Primary family
                              126       1-9.  Secondary family

   63       A-2                      Relationship to Reference Person
                            6,048         &.  Reference person, living alone
                           18,770         0.  Reference person, 2+ persons
                                              in household
                           13,756         1.  Spouse, other spouse NOT in
                                              Armed Forces and living at home
                              151         2.  Spouse, other spouse IN Armed
                                              Forces and living at home
                           21,000         3.  Child of reference person or
                                              spouse
                            1,252         4.  Grandchild of reference person
                                              or spouse
                              645         5.  Parent of reference person or
                                              spouse
                            1,763         6.  Other relative
                               17         7.  Child of military family with
                                              no eligible reference person
                                0         9.  DK or refused
 ______________________________________________________________________

 *Based on family size, number of children under 18 years old and
  family income using the 1995 poverty levels derived from the August,
  1996 Current Population Survey.


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   64         Recode                   FAMILY RELATIONSHIP

                            6,048         1.  Living alone
                            1,076         2.  Living only with non-relative
                           28,297         3.  Living with spouse
                           27,981         4.  Living with relative - other
 ______________________________________________________________________

 65-66        Generated         -      SIZE OF FAMILY*

                                          Unrelated individuals are coded 01
 ______________________________________________________________________

   67         Generated                SIZE OF FAMILY RECODE

                           62,665       1-8.  Number of members
                              737         9.  9+ members
 ______________________________________________________________________

   68         A-2                      PARENT/OTHER ADULT RELATIVE (under 25
                                       years old and never married)

                           13,233          1.  Both parents, no other relative
                            3,521          2.  Mother only
                              324          3.  Father only
                            1,835          4.  Both parents and other 21+
                                               year old adult relative
                            1,271          5.  Mother and other 21+ year old
                                               adult relative
                              152          6.  Father and other 21+ year old
                                               adult relative
                              281          7.  No parent, but one 21+ year
                                               old adult relative
                              427          8.  No parent, but two or more 21+
                                               year old adult relatives
                              164          9.  Unknown
                              849          0.  Other
                           41,345      Blank.  Not applicable (25+ years old
                                               or ever married)
 ______________________________________________________________________

 *Count includes spouse in military but living at home.



                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   69         B-1                      MAJOR ACTIVITY (18+ years old)
              B-8
                           28,283          1.  Working
                            7,516          2.  Keeping house
                            2,504          3.  Going to school
                            6,513          4.  Something else
                              458          5.  Unknown
                           18,128      Blank.  Not applicable (under 18
                                               years old)
 ______________________________________________________________________

   70         G-4                      HEALTH STATUS

                           22,720          1.  Excellent
                           18,116          2.  Very Good
                           15,237          3.  Good
                            4,899          4.  Fair
                            1,697          5.  Poor
                              733          6.  Unknown
 ______________________________________________________________________

   71         Recode                   ACTIVITY LIMITATION STATUS*- (all ages)

                            3,018          1.  Unable to perform major activity
                            3,343          2.  Limited in kind/amount major
                                               activity
                            2,727          3.  Limited in other activities
                           54,314          4.  Not limited (includes unknowns)
 ______________________________________________________________________

   72         Recode                   ACTIVITY LIMITATION STATUS MEASURED BY
                                       "ABILITY TO WORK" (18-69 years old)

                            2,829          1.  Unable to work
                            1,765          2.  Limited in kind/amount of work
                            1,490          3.  Limited in other activities
                           34,269          4.  Not limited (includes unknowns)
                           23,049      Blank.  Not applicable (under 18
                                               years old, 70+ years old)
 ______________________________________________________________________

 *This location is used to categorize persons with limitation of
  activity in the Current Estimates tables.


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   73         B-11                     LIMITATION OF SCHOOL ACTIVITIES
                                       (5-17 years old)

                               81          1.  Unable to attend school
                              438          2.  Attends special school/classes
                               74          3.  Needs special school/classes
                              124          4.  Limited in school attendance
                              282          5.  Limited in other activities
                           12,211          6.  Not limited (includes unknowns)
                           50,192      Blank.  Not applicable (under 5 years
                                               old or 18+ years old)
 ______________________________________________________________________

   74         B-14                     NEEDS HELP WITH PERSONAL CARE
                                       (5-59 years old and limited,
                                       or 60-69 years old)

                              408          1.  Unable to perform personal
                                               care needs
                              822          2.  Limited in performing other
                                               routine needs
                            8,488          3.  Not limited in performing
                                               personal or routine needs
                              404          4.  Unknown
                           53,280      Blank.  Not applicable (under 5
                                               years old; 5-59 years old
                                               not limited; 70+ years old)
 _________________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   75         D-1                      EMPLOYMENT STATUS IN PAST 2 WEEKS
                                       (18+ years old)

                                       In the Labor Force: (1-7)

                                       Currently employed: (1-3)

                           28,767         1.  Worked in past 2 weeks
                              494         2.  Did not work, has job; not
                                              on lay-off and not looking
                                              for work
                               28         3.  Did not work, has job;
                                              looking for work

                                       Unemployed: (4-7)

                               93          4.  Did not work, has job; on
                                               lay-off
                                6          5.  Did not work, has job; on
                                               lay-off and looking for work
                              200          6.  Did not work, has job; unknown
                                               if looking or on lay-off
                              960          7.  Did not work, has no job;
                                               looking for work or on lay-off

                           14,726      8.  Not in Labor Force (18+ years old)

                           18,128      Blank.  Not applicable (under 18 years
                                               old)
 _________________________________________________________________________


                  1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   76         L-6                      CLASS OF WORKER

                           14,726          0.  Not in labor force
                           21,596          1.  Private company
                              756          2.  Federal Government employee
                            1,388          3.  State Government employee
                            2,369          4.  Local Government employee
                              789          5.  Incorporated business
                            2,615          6.  Self-employed
                               29          7.  Without pay
                               35          8.  Never worked
                              971          9.  Unknown
                           18,128      Blank.  Under 18 years old
 _________________________________________________________________________

 77-79        -                        BLANK
 _________________________________________________________________________

 80-81        Recode            -      INDUSTRY RECODE 1

                                       SEE APPENDIX B
 _________________________________________________________________________

 82-83        Recode            -      INDUSTRY RECODE 2

                                       SEE APPENDIX B
 _________________________________________________________________________

 84-86        -                        BLANK
 _________________________________________________________________________

 87-88        Recode            -      OCCUPATION RECODE 1

                                       SEE APPENDIX C
 _________________________________________________________________________

 89-90        Recode            -      OCCUPATION RECODE 2

                                       SEE APPENDIX C
 _________________________________________________________________________


               1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   91         L-R                      RESPONDENT FOR CORE QUESTIONS

                           27,761         1.  Self (entirely)
                            3,242         2.  Self (partly)
                           31,712         3.  Proxy
                              687         4.  Unknown
 ________________________________________________________________________

   92         Recode                   CONDITION LIST ASSIGNED AND ASKED

                           10,548         1.  Condition List 1, Skin and
                                              musculoskeletal
                           10,568         2.  Condition List 2, Impairments
                           10,388         3.  Condition List 3, Digestive
                           10,472         4.  Condition List 4, Miscellaneous
                           10,113         5.  Condition List 5, Circulatory
                           10,575         6.  Condition List 6, Respiratory
                              738         7.  Unknown
 _________________________________________________________________________

 93-94        G-5                      HEIGHT WITHOUT SHOES (18+ years old)

                              363         58.  58 inches or less
                           43,782      59-76.  Number of inches
                              246         77.  77 inches or more
                              883         99.  Unknown
                           18,128      Blank.  Under 18 years old
 _________________________________________________________________________

 95-97        G-5                      WEIGHT WITHOUT SHOES (18+ years old)

                              288          097.  97 pounds or less
                           42,919      098-289.  Number of pounds
                              320          290.  290 pounds or more
                            1,747          999.  Unknown
                           18,128        Blank.  Under 18 years old
 _________________________________________________________________________

 98-99        Recode                   TOTAL RESTRICTED ACTIVITY DAYS IN
                                       PAST TWO WEEKS

                           57,092         00.  None
                            6,310      01-14.  Days
 _________________________________________________________________________

 100-101      D-4                      BED DAYS IN PAST TWO WEEKS

                           59,733         00.  None
                            3,669      01-14.  Days
 _________________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 102-103      D-2                      WORK-LOSS DAYS IN PAST TWO WEEKS

                           61,810         00.  None
                            1,592      01-14.  Days
 _________________________________________________________________________

 104-105      D-3                      SCHOOL-LOSS DAYS IN PAST TWO WEEKS

                           62,431         00.  None
                              971      01-14.  Days
 _________________________________________________________________________

 106-107      D-6                      OTHER DAYS OF RESTRICTED ACTIVITY
                                       IN PAST TWO WEEKS

                           60,449         00.  None
                            2,953      01-14.  Days
 _________________________________________________________________________

 108-110      G-2                      BED DAYS IN PAST 12 MONTHS

                           35,920          000.  None
                           26,460      001-365.  1-365 days
                            1,022          366.  Unknown
 _________________________________________________________________________

   111        Recode                   BED DAYS IN PAST 12 MONTHS

                           35,920         0.   None
                           20,817         1.   1-7 days
                            4,084         2.   8-30 days
                            1,243         3.   31-180 days
                              316         4.   181-365 days
                            1,022         5.   Unknown
 _________________________________________________________________________

 112-114      G-3                      DOCTOR VISITS IN PAST 12 MONTHS

                           15,335          000.  None
                           47,627      001-996.  Visits
                                0          997.  997+ visits
                              440          998.  Unknown
 _________________________________________________________________________

   115        G-3                      INTERVAL SINCE LAST DOCTOR VISIT

                              182          0.  Never
                           48,478          1.  Less than 1 year
                            6,010          2.  1 to less than 2 years
                            4,842          3.  2 to less than 5 years
                            2,128          4.  5 years or more
                            1,762          5.  Unknown
 _________________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 116-117      Generated         -      NUMBER OF CONDITIONS
 _________________________________________________________________________

 118-119      Generated         -      NUMBER OF ACUTE INCIDENCE CONDITIONS
 _________________________________________________________________________

 120-121      Generated         -      NUMBER OF TWO-WEEK DOCTOR VISITS
 _________________________________________________________________________

 122-123      Generated         -      NUMBER OF SHORT-STAY HOSPITAL EPISODES
                                       IN PAST 12 MONTHS
 _________________________________________________________________________

 124-126      Generated         -      SHORT-STAY HOSPITAL EPISODE DAYS IN
                                       PAST 12 MONTHS
 _________________________________________________________________________

 127-128      Generated         -      NUMBER OF SHORT-STAY HOSPITAL EPISODES
                                       IN PAST 12 MONTHS EXCLUDING DELIVERY*
 _________________________________________________________________________

 129-131      Generated         -      SHORT-STAY HOSPITAL EPISODE DAYS IN
                                       PAST 12 MONTHS EXCLUDING DELIVERY*
 _________________________________________________________________________

 132-133      Generated         -      NUMBER OF SHORT-STAY HOSPITAL DISCHARGES
                                       IN PAST 6 MONTHS
 _________________________________________________________________________

 134-136      Generated         -      NUMBER OF DAYS IN SHORT-STAY HOSPITAL
                                       IN PAST 12 MONTHS FOR DISCHARGES IN
                                       PAST 6 MONTHS
 _________________________________________________________________________

 137-138      Generated         -      NUMBER OF SHORT-STAY HOSPITAL DISCHARGES
                                       IN PAST 6 MONTHS EXCLUDING DELIVERY*
 _________________________________________________________________________

 139-141      Generated         -      NUMBER OF DAYS IN SHORT-STAY HOSPITAL
                                       IN PAST 12 MONTHS FOR DISCHARGES IN
                                       PAST 6 MONTHS EXCLUDING DELIVERY*
 _________________________________________________________________________

 *Based on operation codes and reason entered hospital


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 142-143      -                        BLANK
 _________________________________________________________________________

   144        L-9b                     YEARS LIVED IN STATE OF PRESENT
                                       RESIDENCE

                            1,766          1.  Less than 1 year
                            5,762          2.  1 yr., less than 5 yrs.
                            6,429          3.  5 yrs., less than 10 yrs.
                            5,243          4.  10 yrs., less than 15 yrs.
                           32,468          5.  15 years or more
                            3,051          9.  DK refused
                            8,683      Blank.  Not applicable (foreign
                                               born)
 _________________________________________________________________________

   145        L-9c                     YEARS LIVED IN UNITED STATES

                              274          1.  Less than 1 year
                            1,339          2.  1 yr., less than 5 yrs.
                            1,667          3.  5 yrs., less than 10 yrs.
                            1,144          4.  10 yrs., less than 15 yrs.
                            3,997          5.  15 years or more
                              262          9.  DK refused
                           54,719      Blank.  Not applicable (U.S. born)
 _________________________________________________________________________

 146-171      -                 -      BLANK
 _________________________________________________________________________


               1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 172-177      -                 -      FINAL QUARTER BASIC WEIGHT BEFORE
                                       AGE-SEX-RACE/ETHNICITY ADJUSTMENT
                                       (has one implied decimal)
 _________________________________________________________________________

   178                                 SAMPLING QUARTER

                           16,902         1.  Quarter 1
                           19,814         2.  Quarter 2
                           13,470         3.  Quarter 3
                           13,216         4.  Quarter 4
 ______________________________________________________________________

 179-181      -                 -      BLANK
 ______________________________________________________________________

   182        Unit Control             REGION
              File
                           12,500         1.  Northeast
                           13,606         2.  Midwest
                           21,982         3.  South
                           15,314         4.  West
 ______________________________________________________________________

   183        Unit Control             GEOGRAPHIC DISTRIBUTION
              File
                                       MSA Size

                            8,007          1.  5,000,000 or more
                            7,914          2.  2,500,000 - 4,999,999
                           15,124          3.  1,000,000 - 2,499,999
                            6,747          4.  500,000 - 999,999
                            7,811          5.  250,000 - 499,999
                            4,520          6.  100,000 - 249,999
                              810          7.  Under 100,000
                           12,469      Blank.  Non-MSA
 ______________________________________________________________________

 184-185      -                 -      BLANK
 ______________________________________________________________________

   186        Unit Control             MSA - NON-MSA RESIDENCE
              File
                           20,826         1.  In MSA; in Central City
                           30,107         2.  In MSA; not in Central City
                           12,469         3.  Not in MSA
 ______________________________________________________________________

 187-189      -                 -      BLANK
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 190-200      -                 -      CHRONIC CONDITION PREVALENCE AND
                                       INCIDENCE FACTOR (XX.XXXXXXXXX) -
                                       character format with implied
                                       decimal
 _________________________________________________________________________

                                       FINAL BASIC WEIGHT

 201-209      -                 -      QUARTER

 210-218      -                 -      SEMI-ANNUAL (QUARTER/2)

 219-227      -                 -      ANNUAL (QUARTER/4)
 _________________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 _______________________________________________________________________
                                       6.5 WEIGHT

 228-236      -                 -      QUARTER, SEMI-ANNUAL AND ANNUAL*
 _________________________________________________________________________

                                       ESTIMATED RESTRICTED ACTIVITY DAYS
                                       IN PAST 2 WEEKS

 237-245      -                 -      QUARTER, SEMI-ANNUAL AND ANNUAL*
 _________________________________________________________________________

                                       ESTIMATED BED DAYS IN PAST 2 WEEKS

 246-254      -                 -      QUARTER, SEMI-ANNUAL AND ANNUAL*
 _________________________________________________________________________

                                       ESTIMATED WORK-LOSS DAYS IN PAST
                                       2 WEEKS

 255-263      -                 -      QUARTER, SEMI-ANNUAL AND ANNUAL*
 _________________________________________________________________________

                                       ESTIMATED SCHOOL-LOSS DAYS IN PAST
                                       2 WEEKS

 264-272      -                 -      QUARTER, SEMI-ANNUAL AND ANNUAL*
 _________________________________________________________________________

                                       ESTIMATED DOCTOR VISITS IN PAST
                                       12 MONTHS

 273-281      -                 -      QUARTER

 282-290      -                 -      SEMI-ANNUAL

 291-299      -                 -      ANNUAL
 _________________________________________________________________________

                                       ESTIMATED SHORT-STAY HOSPITAL EPISODE
                                       DAYS IN PAST 12 MONTHS

 300-308      -                 -      QUARTER

 309-317      -                 -      SEMI-ANNUAL

 318-326      -                 -      ANNUAL
 _________________________________________________________________________

 327-335      -                 -      ANNUAL ESTIMATED NUMBER OF SHORT-STAY
                                       HOSPITAL EPISODES IN PAST 12 MONTHS
 _________________________________________________________________________
 * Estimates can be made for these periods depending on whether one
   quarter, two quarters or all four quarters of records are used.


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   336        -                 -      BLANK
 ______________________________________________________________________

 337-340      Recode            -      STRATUM FOR VARIANCE ESTIMATION
 ______________________________________________________________________

   341        Recode            -      PSU FOR VARIANCE ESTIMATION
 ______________________________________________________________________

 342-343      Recode            -      SUBSTRATUM FOR VARIANCE ESTIMATION
 ______________________________________________________________________

 344-350      Generated         -      SECONDARY SAMPLING UNIT
 ______________________________________________________________________

   351        Unit Control             TYPE OF PSU
              File
                           41,421      1.  Self representing
                           21,981      2.  Non self representing
 ______________________________________________________________________

   352        Unit Control             PANEL 4
              File
                           63,402      1-4.  Code used to identify
                                             nationally representative
                                             subsamples
 ______________________________________________________________________

   353                          -      NSR STATUS VARIABLE
 ______________________________________________________________________

 354-357                        -      COLLAPSED VARIANCE STRATUM
 ______________________________________________________________________

   358                          -      VARIANCE PSU
 ______________________________________________________________________

 359-399      -                 -      BLANK
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   400        Recode                   DUMMY RECORD FLAG

                            2,586          1.  Dummy record for locations
                                               401-440
                           60,816      Blank.  Not a dummy record
 ______________________________________________________________________

   401        1a                       IS THERE USUAL PERSON/
                                       PLACE FOR MEDICAL CARE

                           52,922          1.  Yes
                            7,353          2.  No
                              186          3.  More than one
                            2,722          8.  Not ascertained
                              219          9.  DK or refused
 ______________________________________________________________________

   402        1b                       ONE PLACE MOST OFTEN
                                       (Has more than one usual
                                       person or place Q 1a = 3)

                              127          1.  Yes
                               47          2.  No
                               10          8.  Not ascertained
                                2          9.  DK or refused
                           63,216      Blank.  NA
 ______________________________________________________________________

 403-404      2                        MAIN REASON NO USUAL SOURCE

                              289         01.  Two or more usual
                                               doctors/places
                            3,377         02.  Doesn't need doctor
                              244         03.  Doesn't like/trust/
                                               believe in doctors
                              140         04.  Doesn't know where to go
                              469         05.  Previous doctor not
                                               available/moved
                            1,689         06.  No insurance/can't
                                               afford it
                                6         07.  Speaks different language
                               32         08.  No care available/
                                               not convenient
                              512         09.  Changed residence
                              327         10.  Other reason
                              261         98.  Not ascertained
                               66         99.  DK or refused
                           55,990      Blank.  NA - Has/don't know if has
                                               one usual source of care
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   405        3a                       ONE PLACE MOST OFTEN
                                       (Q 1a = 2 and Q 2 = 01)

                               97          1.  Yes
                               74          2.  No
                               68          8.  Not ascertained
                                3          9.  DK or refused
                           63,160      Blank.  NA
 ______________________________________________________________________

   406        3b                       PLACE FOR PREVENTIVE CARE
                                       (Q 1a = 2 and Q 2 = 01 and Q 3a
                                       NE 1)

                               81          1.  Yes
                               84          2.  No
                               22          3.  Not ascertained
                                5          4.  DK or refused
                           63,210      Blank.  NA
 ______________________________________________________________________

   407        4a                       GO ANY PLACE IN PAST 12
                                       MONTHS FOR MEDICAL CARE

                            2,728          1.  Yes
                            4,464          2.  No
                            2,912          8.  Not ascertained
                              152          9.  DK or refused
                           53,146      Blank.  NA  - Has a usual source
                                               of care
 ______________________________________________________________________

 408-409      4b                       KIND OF PLACE

                              355         01.  Hospital emergency room
                              210         02.  Urgent care/walk-in clinic
                            1,118         03.  Doctor's office
                              479         04.  Clinic
                              164         05.  Health center
                              139         06.  Hospital outpatient clinic
                               84         07.  HMO/Prepaid group
                               39         08.  Military or VA health
                                               care facility
                               92         09.  Some other place
                               23         98.  Not ascertained
                               25         99.  DK or refused
                           60,674      Blank.  NA
 ______________________________________________________________________


               1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   410        4c                       WOULD STILL GO TO PLACE
                                       (Does not have a usual source of care,
                                       care but did go to a place for medical
                                       care sometime in the past 12 months,
                                       Q 4a = 1)

                            1,462          1.  Yes
                              991          2.  No
                               23          8.  Not ascertained
                              252          9.  DK or refused
                           60,674      Blank.  NA
 ______________________________________________________________________

 411-412      4d                       MAIN REASON WOULD NOT USE PLACE NOW
                                       (Does not have a usual source of care
                                       but did go to a place for medical care
                                       sometime in the past 12 months and
                                       would not use this place now Q 4c = 2)

                              410         01.  Changed residence/moved
                               24         02.  Changed jobs
                               30         03.  Employer changed
                                               insurance coverage
                               64         04.  Former usual source
                                               not available
                                5         05.  Owed money to former source
                               76         06.  Dissatisfied with
                                               former source/like
                                               new source better
                              148         07.  Medical care needs changed
                               14         08.  Former source stopped
                                               taking insurance/coverage
                              199         09.  Some other reason
                               13         98.  Not ascertained
                                8         99.  DK or refused
                           62,411      Blank.  NA
 ______________________________________________________________________

 
                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

    413       Recode                   REGULAR SOURCE OF MEDICAL CARE

                           52,922         1.   Single regular source
                              224         2.   Multiple regular sources,
                                               but sees one most often
                              204         3.   Multiple regular sources,
                                               but no one source seen
                                               most often
                            2,524         4.   No current regular source
                                               but had a regular source
                                               sometime in the past year
                            4,358         5.   No current regular source
                                               of care and none in past
                                               year
                              229         6.   No current regular source
                                               and unknown if any in past
                                               year
                            2,722         8.   Not ascertained
                              219         9.   DK or refused
 ______________________________________________________________________

 414-415      5a                       KIND OF PLACE

                              759         01.  Hospital emergency room
                              712         02.  Urgent care/walk-in clinic
                           35,675         03.  Doctor's office
                            7,430         04.  Clinic
                            1,815         05.  Health center
                            1,381         06.  Hospital outpatient clinic
                            3,713         07.  HMO/prepaid group
                              763         08.  Military or VA health care
                                               facility
                              268         09.  Some other place
                              516         98.  Not ascertained
                              114         99.  DK or refused
                           10,256      Blank.  NA - Does not have/DK
                                               if have a usual source
                                               of care
 ______________________________________________________________________

                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   416        5b                       IS THERE PARTICULAR PERSON
                                       USUALLY SEEN

                           44,452          1.  Yes
                            6,290          2.  No
                              587          8.  Not ascertained
                              346          9.  DK or refused
                           11,727      Blank.  NA - Does not have/DK if
                                               have a usual source
                                               of care
 ______________________________________________________________________

   417        6a                       TYPE OF HEALTH PROFESSIONAL
                                       (Usually sees a particular person
                                       when goes to usual source of care.
                                       Q 5b = 1)

                           43,371          1.  Doctor
                               79          2.  Nurse
                              222          3.  Nurse practitioner
                              180          4.  Physician's assistant
                               43          5.  Chiropractor
                               43          6.  Some other professional
                              500          8.  Not ascertained
                               14          9.  DK or refused
                           18,950      Blank.  NA
 ______________________________________________________________________

   418        6b                       TYPE OF DOCTOR
                                       (Usually sees a particular doctor
                                       when goes to usual source of care
                                       Q 6a = 1)

                           40,294          1.  Family doctor/GP/
                                               internist/pediatrician
                            1,047          2.  Obstetrician/gynecologist
                            1,434          3.  Other specialist
                              451          8.  Not ascertained
                              145          9.  DK or refused
                           20,031      Blank.  NA
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   419        7                        LAST TIME WENT TO USUAL
                                       PLACE (Has a usual place
                                       for medical care)

                            1,322          0.  Hasn't been there
                                               yet/never
                           20,540          1.  Less than 3 months ago
                            9,747          2.  At least 3 months,
                                               less than 6 months ago
                            9,693          3.  At least 6 months,
                                               less than 1 year ago
                            6,342          4.  At least 1 year,
                                               less than 2 years ago
                            4,098          5.  Two or more years ago
                              518          8.  Not ascertained
                              886          9.  DK or refused
                           10,256      Blank.  NA
 ______________________________________________________________________

   420        8                        SAME PLACE FOR ROUTINE CARE
                                       (Has a usual place for medical
                                       care)

                           50,176          1.  Yes
                            1,793          2.  No
                              914          8.  Not ascertained
                              263          9.  DK or refused
                           10,256      Blank.  NA
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   421        Recode                   RELATIONSHIP BETWEEN SOURCES OF
                                       SICK AND PREVENTIVE CARE

                           50,176          1.  Has the same usual source for
                                               sick and routine/preventive care
                            1,793          2.  Has a usual source for sick care,
                                               but it is not usual source of
                                               routine/routine/preventive care
                                               (may include persons with no
                                               usual source of
                                               routine/preventive care)
                            1,177          3.  Has a usual source of sick care,
                                               but unknown if has a usual source
                                               of routine/preventive care
                               81          4.  Has two or more usual sources of
                                               sick care and has a source for
                                               routine/preventive care
                               84          5.  Has two or more usual sources
                                               of sick care, but does not
                                               have a source for routine/
                                               preventive care
                               27          6.  Has two or more usual sources
                                               of sick care, but unknown if
                                               has a usual source of
                                               routine/preventive care
                            7,123          7.  No usual source of sick care;
                                               not asked about preventive
                                               care
                            2,722          8.  Not ascertained
                              219          9.  DK or refused
 _____________________________________________________________________

   422        9                        GO TO OTHER PLACE PAST 12 MONTHS
                                       (Has a usual place for medical
                                       care)

                           15,094          1.  Yes
                           36,270          2.  No
                            1,397          8.  Not ascertained
                              385          9.  DK or refused
                           10,256      Blank.  NA
 ______________________________________________________________________


                  1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   423        10b                      CHANGED PLACE FOR ROUTINE CARE

                            4,548          1.  Yes
                           55,862          2.  No
                            2,841          8.  Not ascertained
                              151          9.  DK or refused
 ______________________________________________________________________

 424-425      10d                      MAIN REASON FOR CHANGE LAST TIME

                            1,503         01.  Changed residence
                              197         02.  Changed jobs
                              643         03.  Employer changed
                                               insurance coverage
                              347         04.  Former usual source
                                               not available
                                4         05.  Owed money to former source
                              673         06.  Dissatisfied with former
                                               source/like new source
                                               better
                              308         07.  Medical care needs changed
                              126         08.  Former source stopped
                                               taking insurance/coverage
                              639         09.  Some other reason
                              103         98.  Not ascertained
                                5         99.  DK or refused
                           58,854      Blank.  NA - Did not/DK change
                                               usual place of medical
                                               care in past 12 months
 ______________________________________________________________________

   426        11b                      NEEDED CARE BUT NOT ABLE TO GET IT

                            1,703          1.  Yes
                           58,773          2.  No
                            2,792          8.  Not ascertained
                              134          9.  DK or refused
 ______________________________________________________________________


                  1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

 427-428      11d                      MAIN REASON DIDN'T GET CARE

                              801         01.   Could not afford it
                              278         02.   No insurance
                               32         03.   Doctor did not
                                                accept Medicaid/
                                                insurance plan
                               50         04.   Insurance didn't cover
                               30         05.   Not serious enough
                               34         06.   Wait too long in
                                                clinic/office
                              141         07.   Difficulty getting
                                                an appointment
                               19         08.   Doesn't like/trust/
                                                believe in doctors
                               33         09.   No doctor available
                                8         10.   Didn't know where to go
                               14         11.   No way to get there
                                7         12.   Hours not convenient
                                0         13.   Speak a different language
                                1         14.   Health of another family
                                                member interfered
                                9         15.   Clinic/office not accessible
                              135         16.   Other reason
                              106         98.   Not ascertained
                                5         99.   DK or refused
                           61,699      Blank.   NA - Obtained medical
                                                care when needed during
                                                the past 12 months
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   429        11e                      LACK OF INSURANCE OR MONEY A REASON

                              121          1.  Yes
                              316          2.  No
                              102          3.  Not ascertained
                                3          9.  DK or refused
                           62,860      Blank.  NA - Obtained medical care
                                               when needed during the 12 months
                                               or already mentioned that money
                                               or lack of insurance was a reason
 ______________________________________________________________________

    430       12b                      DELAYED SEEKING MEDICAL
                                       CARE BECAUSE OF COST

                            4,507          1.  Yes
                           55,972          2.  No
                            2,812          8.  Not ascertained
                              111          9.  DK or refused
 ______________________________________________________________________

   431        13b                      NEEDED DENTAL CARE BUT
                                       COULD NOT GET IT

                            4,800          1.  Yes
                           55,603          2.  No
                            2,833          8.  Not ascertained
                              166          9.  DK or refused
 ______________________________________________________________________

   432        14b                      NEEDED PRESCRIPTION MEDICINES
                                       BUT COULD NOT GET THEM

                            1,504          1.  Yes
                           58,945          2.  No
                            2,781          8.  Not ascertained
                              172          9.  DK or refused
 ______________________________________________________________________

   433        15b                      NEEDED EYEGLASSES BUT
                                       COULD NOT GET THEM

                            1,874          1.  Yes
                           58,379          2.  No
                            2,947          8.  Not ascertained
                              202          9.  DK or refused
 ______________________________________________________________________


                   1996 NHIS ACCESS TO CARE PUBLIC USE FILE

 ______________________________________________________________________
   File
 Locations    Item No.  Frequency        Items and Codes
 ______________________________________________________________________

   434        16b                      NEEDED MENTAL HEALTH CARE
                                       BUT COULD NOT GET IT

                              348          1.  Yes
                           60,046          2.  No
                            2,849          8.  Not ascertained
                              159          9.  DK or refused
 ______________________________________________________________________

 435-436      -                 -      BLANK
 ______________________________________________________________________

 437-438      Check                    CHECK ITEM (Reference Person
              Item A5                  Only) PERSON WHO ANSWERED MOST
                                       QUESTIONS

                              865         00.   Respondent not ascertained
                           59,837      01-28.   Person number
                                0      30-97.   Person number
                              101         98.   Active duty military
                               13         99.   Non household member
                            2,586      Blank.   Dummy record
 ______________________________________________________________________

   439        Recode                   RESPONDENT FOR SUPPLEMENT STATUS

                           23,701          1.  Self
                           36,319          2.  Proxy
                              796          9.  Unknown respondent
                            2,586      Blank.  Dummy record
 ____________________________________________________________________

   440        -                 -      BLANK
 ______________________________________________________________________


                                    APPENDIX A


                      There is no Appendix for this document


                                        B-1

                                    APPENDIX B
                             INDUSTRY RECODES OUTLINE            Revised in 1995
 _______________________________________________________________________________
     Recodes
 ---------------------
  No. 1  No. 2
  Chrs.  Chrs.                           Industry Title            SIC Code*
  80-81  82-83
 _______________________________________________________________________________

    01    01                     AGRICULTURE                 01-02,071-072,074-
                                                             076,078

    02    01                     FORESTRY AND FISHERIES      08-09
 _______________________________________________________________________________

    10    02                     MINING                      10,12-14
 _______________________________________________________________________________

    20    03                     CONSTRUCTION                15-17
 _______________________________________________________________________________

 (30-34,
  40-46) (04)                    MANUFACTURING:

 (30-34)                         NONDURABLE GOODS

    30    04                     Food and kindred products   201-209


    31    04                     Textile mill and finished   221-229,231-239
                                 textile products

    32    04                     Printing, publishing and    271-279
                                 allied industries

    33    04                     Chemicals and allied        281-287,289
                                 products

    34    04                     Other nondurable goods      21,261-263,265,267,
                                                             291,295,299,301-
                                                             306,308,311,313-
                                                             317,319

 _______________________________________________________________________________

 *Standard Industrial Classification

                                    APPENDIX B
                             INDUSTRY RECODES OUTLINE           Revised in 1995
 _______________________________________________________________________________
     Recodes
 -----------------
  No. 1  No. 2
  Chrs.  Chrs.                   Industry Title              SIC Code*
  80-81  82-83
 _______________________________________________________________________________

 (30-34,
  40-46) (04)                    MANUFACTURING: - continued

 (40-46)                         DURABLE GOODS

    40    04                     Furniture, lumber and wood  241-245,249,25

    41    04                     Primary metal industries    331-332,334,3331,
                                                             3334,3339,3351,
                                                             3353-3357,3363-
                                                             3366,3369,339

    42    04                     Fabricated metal            341-349
                                 industries, including
                                 ordnance

    43    04                     Machinery, except           351-359
                                 electrical

    44    04                     Electrical machinery,       361-367,369
                                 equipment and supplies

    45    04                     Transportation equipment    371-376,379

    46    04                     Other and not specified     321-329,381-382,
                                 durable goods               384-387,39


 _______________________________________________________________________________
 *Standard Industrial Classification

                                    APPENDIX B
                             INDUSTRY RECODES OUTLINE           Revised in 1995
 _______________________________________________________________________________
     Recodes
 -----------------
  No. 1  No. 2
  Chrs.  Chrs.                   Industry Title              SIC Code*
  80-81  82-83
 _______________________________________________________________________________

 (50-54) (05)                    TRANSPORTATION, COMMUNICATIONS
                                 AND OTHER PUBLIC UTILITIES

    50    05                     Railroads                   40

    51    05                     Trucking service and        421-423
                                 warehousing

    52    05                     Other transportation        41,43-47


    53    05                     Communications              481-484,489

    54    05                     Utilities and sanitary      491-497
 _______________________________________________________________________________

    60    06                     WHOLESALE TRADE             501-509,511-519
 _______________________________________________________________________________

 *Standard Industrial Classification

                                   APPENDIX B
                            INDUSTRY RECODES OUTLINE            Revised in 1995
 _______________________________________________________________________________
     Recodes
 -----------------
  No. 1   No. 2
  Chrs.   Chrs.                  Industry Title              SIC Code*
  80-81   82-83
 _______________________________________________________________________________

 (61-65) (07)                    RETAIL TRADE

    61    07                     General merchandise stores  531,533,539

    62    07                     Food, bakery and dairy      541-546,549
                                 stores

    63    07                     Automotive dealers and      551-557,559
                                 gasoline stations

    64    07                     Eating and drinking places  58

    65    07                     Other and not specified     521,523,525-527,56,
                                 retail trade                571-572,5731,5734-
                                                             5736,591-594,5961-
                                                             5963,598,5992-5995,
                                                             5999
 _______________________________________________________________________________

 (70-71) (08)                    FINANCE, INSURANCE, AND REAL
                                 ESTATE

    70    08                     Banking and credit          60-61
                                 agencies

    71    08                     Insurance, real estate,     62-65,67
                                 and other finance
 _______________________________________________________________________________

 *Standard Industrial Classification


                                   APPENDIX B
                            INDUSTRY RECODES OUTLINE            Revised in 1995

 _______________________________________________________________________________
     Recodes
 -----------------
  No. 1   No. 2
  Chrs.   Chrs.                  Industry Title              SIC Code*
  80-81   82-83
 _______________________________________________________________________________

 (75-85) (09-12)                 SERVICES:

 (75-76) (09)                    BUSINESS AND REPAIR SERVICES

    75    09                     Business services           731-738,751,752,
                                                             7542

    76    09                     Repair services             753,7549,762-764,
                                                             7692,7694,7699

 (77-78) (10)                    PERSONAL SERVICES

    77    10                     Private households          88

    78    10                     Other personal services     701-704,721-726,729


    79    11                     ENTERTAINMENT AND           781-784,791-794,799
                                 RECREATION SERVICES

 (80-85) (12)                    PROFESSIONAL AND RELATED
                                 SERVICES

    80    12                     Hospitals                   806

    81    12                     Health services, except     801-803,8041-8043,
                                 hospitals                   8049,805,807-809

    82    12                     Elementary and secondary    821-822
                                 schools and colleges

    83    12                     Other educational services  823-824,829

    84    12                     Social services, religious  832-833,835-836,
                                 and membership              839,84,861-866,869
                                 organizations

    85    12                     Legal, engineering and      81,871-874,899
                                 other professional services
 _______________________________________________________________________________

 *Standard Industrial Classification

                                    APPENDIX B
                             INDUSTRY RECODES OUTLINE           Revised in 1995
 _______________________________________________________________________________
    Recodes
 ----------------
  No. 1  No. 2
  Chrs.  Chrs.                   Industry Title              SIC Code*
  80-81  82-83
 _______________________________________________________________________________

    90    13                     PUBLIC ADMINISTRATION       911-913,919,92-97

 _______________________________________________________________________________

    95    14                     UNKNOWN INDUSTRY            -
                                 (Includes never worked)

 _______________________________________________________________________________

    96    14                     REFUSED, CLASSIFIED, ETC.
 _______________________________________________________________________________

    97    15                     NOT IN LABOR FORCE - codes Blank
                                 and 8 in current activity recode
                                 (loc. 75) (Under 18 or 18+ and
                                 not in Labor Force).
 _______________________________________________________________________________

    98    16                     ARMED FORCES (excludes Reserves
                                 and National Guard)
 _______________________________________________________________________________

 *Standard Industrial Classification

                                   APPENDIX B
                            INDUSTRY RECODE TITLES
 _______________________________________________________________________________

                                                             Recode No. 1
   Code                  Titles                              Inclusions
 _______________________________________________________________________________

    01    AGRICULTURE, FORESTRY AND FISHERIES                01,02

    02    MINING                                             10

    03    CONSTRUCTION                                       20

    04    MANUFACTURING                                      30-34, 40-46

    05    TRANSPORTATION, COMMUNICATIONS AND OTHER PUBLIC    50-54
          UTILITIES

    06    WHOLESALE TRADE                                    60

    07    RETAIL TRADE                                       61-65

    08    FINANCE, INSURANCE, AND REAL ESTATE                70-71

    09    BUSINESS AND REPAIR SERVICES                       75-76

    10    PERSONAL SERVICES                                  77-78

    11    ENTERTAINMENT AND RECREATION SERVICES              79

    12    PROFESSIONAL AND RELATED SERVICES                  80-85

    13    PUBLIC ADMINISTRATION                              90

    14    UNKNOWN (includes never worked, refused,           95-96
          classified, etc.)

    15    NOT IN LABOR FORCE                                 97

    16    ARMED FORCES                                       98


                                   C-1

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 __________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 __________________________________________________________________________

 (01-03)    (01)     EXECUTIVE, ADMINISTRATIVE,          -
                     AND MANAGERIAL OCCUPATIONS

   01       01       Officials and administrators,       111-113
                     public administration

   02       01       Managers and administrators,        121-128,131-
                     except public administration        1344,1351-
                                                         1354,1359,
                                                         136-139

   03       01       Management related occupations      1412,1414-1415,
                                                         1419,142-143,
                                                         1442-1443,1449,
                                                         145,1472-
                                                         1473,149
 __________________________________________________________________________

 *Standard Occupational Classification

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 __________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 __________________________________________________________________________

 (04-11)   (02)      PROFESSIONAL SPECIALTY OCCUPATIONS      -

   04       02       Engineers                           1622-1628,1632-
                                                         1637,1639

   05       02       Architects and surveyors            161,164

   06       02       Natural mathematical and            171-172,1732-
                     computer scientists                 1733,1739,
                                                         1842-1843,
                                                         1845-1847,1849,
                                                         1852-1855

   07       02       Health diagnosing occupations       261-262,27,281,
                                                         283,289

   08       02       Health assessment and               29,301-302,
                     treating occupations                3031-3034,3039,
                                                         304

   09       02       Teachers, librarians and            2212-2218,
                     Counselors                          2222-2228,
                                                         2231-2238,
                                                         2242-2247,
                                                         2249,231-233,
                                                         235,236,239,24,
                                                         251,252

   10       02       Writers, artists,                   34,321-329,
                     entertainers and athletes           331-333,398

   11       02       Other professional specialty        1912-1916,
                     occupations                         1919,192,
                                                         2032-2033,
                                                         2042,2049,
                                                         211-212
 __________________________________________________________________________
 *Standard Occupational Classification.

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 __________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

 (12-13)   (03)      TECHNICIANS AND RELATED            -
                     SUPPORT OCCUPATIONS

   12       03       Health technologists and           362-366,369
                     technicians

   13       03       Technologists, technicians         3711-3713,3719,
                     except health                      372-373,382,
                                                        3831-3833,
                                                        384,389,
                                                        392-393,396,
                                                        3971-3972,
                                                        3974,399,
                                                        825
 ___________________________________________________________________________

 (14-16)   (04)      SALES OCCUPATIONS                  -

   14       04       Supervisors and proprietors        40

   15       04       Sales representatives,             4122-4124,
                     commodities and finance            4152-4153,
                                                        421,423-424

   16       04       Other sales                        4342-4348,4351-
                                                        4354,4356,4359,
                                                        4362-4367,4369,
                                                        444-447,449
 __________________________________________________________________________

 *Standard Occupational Classification

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 __________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

 (17-21)   (05)      ADMINISTRATIVE SUPPORT             -
                     OCCUPATIONS, INCLUDING CLERICAL

   17       05       Computer equipment operators       4612-4613

   18       05       Secretaries, stenographers         4622-4624
                     and typists

   19       05       Financial records processing       4712-4713,
                     occupations                        4715-4716,
                                                        4718

   20       05       Mail and message distributing      4742-4745

   21       05       Other administrative support       4511-4514,4516,
                                                        4519,4521-4529,
                                                        463,4642-4645,
                                                        4649,4662-4664,
                                                        4692,4694,4696,
                                                        4699,4722-4723,
                                                        4729,4732-4733,
                                                        4739,4751-4759,
                                                        4782-4784,4786-
                                                        4787,4791-4795,
                                                        4799

   22       06       Private household occupations      502-507,509
 ___________________________________________________________________________

 *Standard Occupational Classification.

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 ___________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

 (23-24)   (07)      PROTECTIVE SERVICE OCCUPATIONS

   23       07       Police and firefighters             5111-5112,
                                                         5122-5123,
                                                         5132-5134

   24       07       Other protective service            5113,5142,5144,
                     occupations                         5149
 ___________________________________________________________________________

 (25-28)   (08)      SERVICE OCCUPATIONS, EXCEPT
                     PROTECTIVE AND HOUSEHOLD

   25       08       Food service                        5211-5219

   26       08       Health service                      5232-5233,5236

   27       08       Cleaning and building service       5241-5242,
                                                         5244-5246,5249

   28       08       Personal service                    5251-5258,5262-
                                                         5264,5269
 ___________________________________________________________________________

 (29-31)   (09)      FARMING, FORESTRY AND FISHING
                     OCCUPATIONS

   29       09       Farm operators and managers         5512-5515,5522-
                                                         5525

   30       09       Farm workers and other              5611-5619,
                     agricultural workers                5621-5622,
                                                         5624-5625,5627

   31       09       Forestry and fishing                571-573,579,
                     occupations                         583-584,8241(pt.)
 ___________________________________________________________________________

 *Standard Occupational Classification.

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 ___________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

 (32-34)   (10)      PRECISION PRODUCTION, CRAFT
                     AND REPAIR OCCUPATIONS

   32       10       Mechanics and repairers            60,6111-6118,
                                                        613-614,6151-
                                                        6159,616,6171-
                                                        6179

   33       10       Construction and extractive        6311-6316,6318,
                     trades                             632,6412-
                                                        6414(pt.),6422,
                                                        6424,6432-6433,
                                                        6442-6444,645,
                                                        6462-6468,6472-
                                                        6476,6479,652-
                                                        654,656

   34       10       Precision production               67,71,
                     occupations                        6811-6814,
                                                        6816-6817,
                                                        6821-6824,
                                                        6829,6831-6832,
                                                        6835,6839,6844,
                                                        6852-6854,6856,
                                                        6859,6861-6862,
                                                        6864-6867,6869,
                                                        6871-6873,6879,
                                                        6881-6882,691-
                                                        696,7477(pt.),
                                                        7668,7677(pt.),
                                                        7752,828
 ___________________________________________________________________________

 *Standard Occupational Classification

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 ___________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

                     OPERATORS, FABRICATORS AND
                     LABORERS

 (35-36)   (11)      MACHINE OPERATORS, ASSEMBLERS
                     AND INSPECTORS

   35       11       Machine operators and              6841-6842,6849,
                     tenderers, except precision        6855,6863,6868,
                                                        7312-7319,7322,
                                                        7324,7326,7329,
                                                        7339,7342-7344,
                                                        7349,7431-7435,
                                                        7439,7443-7444,
                                                        7449,7451-7452,
                                                        7459,7462-7463,
                                                        7467,7472,7474,
                                                        7476-7478,7479,
                                                        7512-7519,7522,
                                                        7529,7539,7542-
                                                        7544,7549,7631-
                                                        7636,7639,7642-
                                                        7644,7649,7651-
                                                        7652,7654-7659,
                                                        7661-7667,7669,
                                                        7671-7676,
                                                        7677(pt.),
                                                        7678-7679

   36       11       Fabricators, assemblers,           7332-7333,7532-
                     inspectors and samplers            7533,7714,7717,
                                                        72,774,7753-
                                                        7759,782-785,787
 ___________________________________________________________________________

 *Standard Occupational Classification

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 ___________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

 (37-39)   (12)      TRANSPORTATION AND MATERIAL
                     MOVING OCCUPATIONS

   37       12       Motor vehicle operators            8111,8212-8216,
                                                        8218-8219,874

   38       12       Other transportation, except       8113,8232-8233,
                     motor vehicles                     8239,8241(pt.),
                                                        8242-8245

   39       12       Material moving equipment          812,8312-8319
                     operators
 ___________________________________________________________________________

 (40-41)   (13)      HANDLERS, EQUIPMENT CLEANERS,
                     HELPERS AND LABORERS

   40       13       Construction laborers              871

   41       13       Freight, stock and material        85,861-863,
                     handlers                           8641-8646,
                                                        8648,865,
                                                        8722-8726,873,
                                                        875,8761,8769
 ___________________________________________________________________________

 * Standard Occupational Classification

                               APPENDIX C

                       OCCUPATION RECODE OUTLINE           Revised in 1995
 ___________________________________________________________________________
     Recodes
 ----------------
 No. 1    No. 2
 Chrs.    Chrs.         Occupation Title                SOC Code*
 87-88    89-90
 ___________________________________________________________________________

  95       14         UNKNOWN OCCUPATION
                      (Includes never worked)
 ___________________________________________________________________________

  96       14         REFUSED, CLASSIFIED, ETC.
 ___________________________________________________________________________

  97       15         NOT IN LABOR FORCE - codes Blank
                      and 8 in current activity recode
                      (Loc. 75).  (Under 18 or 18+
                      and Not in Labor Force)
 ___________________________________________________________________________

  98       16         MILITARY
 ___________________________________________________________________________

  *Standard Occupational Classification

                              APPENDIX C
                        OCCUPATION RECODE TITLES

 ___________________________________________________________________________

                                                             Recode No. 1
 Code                     Titles                             Inclusions
 ___________________________________________________________________________

        MANAGERIAL AND PROFESSIONAL SPECIALTY OCCUPATIONS

  01    EXECUTIVE, ADMINISTRATIVE AND MANAGERIAL OCCUPATIONS   01-03

  02    PROFESSIONAL SPECIALTY OCCUPATIONS                     04-11

              TECHNICAL, SALES AND ADMINISTRATIVE SUPPORT
                           OCCUPATIONS

  03    TECHNICIANS AND RELATED SUPPORT OCCUPATIONS            12-13

  04    SALES OCCUPATIONS                                      14-16

  05    ADMINISTRATIVE SUPPORT OCCUPATIONS, INCLUDING          17-21
        CLERICAL

                            SERVICE OCCUPATIONS

  06    PRIVATE HOUSEHOLD OCCUPATIONS                          22

  07    PROTECTIVE SERVICE OCCUPATIONS                         23-24

  08    SERVICE OCCUPATIONS, EXCEPT PROTECTIVE AND             25-28
        HOUSEHOLD

  09    FARMING, FORESTRY AND FISHING OCCUPATIONS              29-31

  10    PRECISION PRODUCTION, CRAFT AND REPAIR OCCUPATIONS     32-34

               OPERATORS, FABRICATORS AND LABORERS

  11    MACHINE OPERATORS, ASSEMBLERS AND INSPECTORS           35-36

  12    TRANSPORTATION AND MATERIAL MOVING OCCUPATIONS         37-39

  13    HANDLERS, EQUIPMENT CLEANERS, HELPERS AND LABORERS     40-41

  14    UNKNOWN OCCUPATION (includes never worked, refused,    95-96
        classified, etc.)

  15    NOT IN LABOR FORCE                                     97

  16    MILITARY                                               98




                VARIANCE ESTIMATION FOR PERSON DATA USING THE
                 NHIS PUBLIC USE PERSON DATA TAPE, 1995-2004

 April 17, 1998

 About this document:

 This document provides basic design information about the 1995-2004 NHIS and
 presents methods to compute standard errors for each annually released person-
 level database.  This document focuses upon a full-sample NHIS Core survey that
 is anticipated for each data collection year.  For some years the full-sample
 methods need to be modified to account for design changes.  In particular, the
 1996 NHIS has a sample design quite different from the 1995 NHIS.  Also,
 Supplemental surveys may require modified methods.  Some notes about these
 modifications appear at the end of this document.



 Contents

 VARIANCE ESTIMATION FOR PERSON DATA USING THE NHIS PUBLIC
 USE PERSON DATA TAPE, 1995                                  Pages 2-11

 Notes for the 1995 NHIS Year 2000 supplement                Page 12

 Notes for the 1996 NHIS                                     Pages 13-16




                VARIANCE ESTIMATION FOR PERSON DATA USING THE
                    NHIS PUBLIC USE PERSON DATA TAPE, 1995


 Introduction:  The data collected in the NHIS are obtained through a complex
 sample design involving stratification, clustering, and multistage sampling,
 and the final weights are subject to several adjustments.  Any variance
 estimation methodology must involve numerous simplifying assumptions about
 the design and weighting.  We provide some oversimplified conceptual NHIS
 design structures that should allow users of this Public Use Data Set to
 compute reasonably accurate standard errors.

 There are several available software packages for analyzing complex samples.
 A comparison is beyond the scope of this document, but an Internet web page
 Summary of Survey Analysis Software currently located at
 http://www.fas.harvard.edu/~stats/survey-soft/survey-soft.html provides
 references and discussion.  At NCHS the software package SUDAAN  has been used
 to produce standard errors.  In this document SAS and SUDAAN computer code
 is provided, but without guarantees of any kind.  The computer code and
 methods are subject to change without notification to the user.  The entire
 risk as to the results and performance is assumed by the user.  NCHS
 recommends that any analysis of NHIS data be done under the supervision of a
 statistician who understands the implications of complex-sample design
 surveys.

 Conceptual NHIS design for 1995  The U.S. Bureau of the Census partitions the
 state counties or equivalents along with metropolitan areas into a universe
 of about 1900 Primary Sampling Units (PSUs) (note, PSUs may be combined
 counties) to provide the primary sampling areas for its many national
 surveys.  For the NHIS these universe PSUs are partitioned into geographical
 strata at the state level.  Some of the larger universe PSUs are self-
 representing (SR), i.e., they are in the NHIS with certainty.  The other PSUs
 are called non-self-representing (NSR) or non-certainty PSUs.  Within each
 state the NSR PSUs are partitioned into strata based upon similarity of PSU
 characteristics.  Within each NSR stratum 2 PSUs are selected using Durbin's
 probability proportional to size (PPS) sampling method using the population
 as a measure of size.  (In some smaller states only 1 PSU is drawn PPS).  The
 SR PSUs are equivalent to strata, but historically they have been referred to
 as PSUs.  (PPS and Durbin sampling are discussed in Chapter 9A of Cochran
 (1977)).

 Within a sampled NSR or SR PSU the geography is partitioned into smaller
 geographical clusters which are used to form the universe of secondary
 sampling units (SSUs).  These SSUs are then partitioned into density strata
 based upon black and Hispanic population concentration as determined by the
 1990 Decennial Census.  An additional strata for new construction since the
 last Decennial Census is also created.  Within each density stratum SSUs are
 sampled at different rates to meet different design objectives.  Within each
 sample SSU, all households containing black or Hispanic persons are sampled,
 while all other households are subsampled.  Supplemental NHIS surveys may
 require additional sampling at SSU, household, or family levels.

 The fundamental sampling weights are created such that under ideal sampling
 conditions, unbiased estimators for each level of sampling are available.
 In practice, however, the final sampling weights are adjusted for non-
 response, and ratio adjusted.  Furthermore, in 1995 a government shutdown
 resulted in three lost weeks of sample which resulted in further weighting
 adjustments.  The most important adjustment is a quarterly post-
 stratification to 90 age/sex/race/ethnicity Census control totals.

 For variance estimation purposes, NCHS treats the NHIS as a two-stage sample.
 The PSU probabilities of selection are known, and the SSUs are treated as
 sampled with replacement within PSU density strata.  Sampling weights are
 adjusted by postratification.  With these assumptions the SUDAAN software is
 used to compute variances.  Much of the design information, state, density
 strata, and Durbin probabilities can be used to identify the smaller
 geographical areas.  NCHS forbids the disclosure of information which may
 compromise the confidentiality promised to survey respondents, so some design
 information is not provided with the Public Use Data.  While all design
 information is not available to the public, variance estimation methods
 exist which provide similar results to the NCHS internally used
 methodology.  Two methods are described below.

 Design Information Available on the NHIS Public Use Databases.

 CAUTION For 1996 databases, refer to the Notes at the end of this document.

 The following variables are used to produce code for variance estimation.
 Field locations below are from the PERSON level database, but may change on
 other databases; the user should check the file documentation.


 Variable      Tape
 Name          Location      Field Label

 STRAT_V       337-340       'STRATA FOR VARIANCE ESTIMATION'

 PSU_V         341           'PSU FOR VARIANCE ESTIMATION'

 SUB_V         342-343       'SUBSTRATUM FOR VARIANCE ESTIMATION'

 SSU           344-350       'SECONDARY SAMPLING UNIT'

 PANEL         352           'PANEL 4'

 TYPE_PSU      351           'TYPE OF PSU'

 WTF           219-227       'FINAL BASIC WEIGHT'

 Two methods of variance estimation are provided.


 Method 1 - 187 Strata containing 2 PSUs per stratum sampled with replacement

 Here, the NHIS universe has been partitioned into 187 strata.  Most of the
 original NHIS strata and PSUs retain their original sampling structure with
 two PSUs being sampled per stratum, but a few strata have been collapsed, and
 in the largest self-representing strata, two pseudo-PSUs have been created.
 All PSUs are treated as sampled with replacement within their respective
 strata.  This method will provide somewhat conservative standard errors,
 and the standard error estimator itself has less stability than the standard
 error estimator described by Method 2 below.  Method 1 should be applicable
 to many complex survey sample design computer programs which require exactly
 2 sampled PSUs per stratum.  This method is robust when analyzing subsetted
 data (See the section "Subsetted Data Analysis" below).

 Coding required (SAS  code provided):

      STRATUM  = STRAT_V;

      PSU = PANEL;

      IF (PSU_V = 5) THEN PSU = INT((PANEL + 1)/2);

      IF(PSU_V = 8) THEN STRATUM  = 553;

      IF((TYPE_PSU = 1) AND (PSU_V IN (2,4))) THEN STRATUM =
      (STRAT_V -1);

      IF((STRAT_V  = 921)  AND (PSU_V  = 3)) THEN STRATUM = 901;

 As a check the user should observe 374 PSUs when using the full database.


 For the above simplification of the NHIS sample design structure, the
 following SUDAAN design statements may be used. (Note, the input file must
 first be sorted by STRATUM and PSU variables.)

      PROC ...  DESIGN = WR;
      NEST      STRATUM PSU ;
      WEIGHT    WTF;

 See the Section "Worked SUDAAN Examples" below for further discussion.

 Method 2 - Multiple PSUs per Stratum design sampled with replacement

 This method provides for more statistically efficient variance estimation
 than Method 1, since it makes better use of the sampling design information.
 Its application is limited to software that can handle multiple PSUs per
 stratum, e.g., SUDAAN.  For this method the original certainty PSUs are
 partitioned by aggregations of the original race-ethnic density strata used
 in sampling.  The first randomly sampled unit is actually the SSU variable
 which is now treated as the PSU variable.  (Note, a certainty  PSU unit
 contributes nothing to the variance at the PSU sampling level.)  Non-
 certainty-strata PSUs are treated as being sampled with replacement within
 their respective strata.  Except for a few special cases, the non-certainty
 PSUs have exactly the same structure in both Methods 1 and 2.


 Coding required, (SAS  code provided ):

 IF TYPE_PSU = 1 THEN DO;  /* certainty strata PSUs  */

       STRATUM = STRAT_V*1000 + SUB_V;
          PSU  = SSU  ;
          END;

  ELSE DO ;                /* non-certainty PSU   */;

       STRATUM = STRAT_V ;
           PSU  =   PSU_V ;
          END;

 As a check, the user should observe the following counts:

 Certainty Strata PSUs         4079
 Non-certainty Strata PSUs      259
 Total PSUs                    4338

 For the  Method 2 design structure, the following SUDAAN  design statements
 may be used. (Note, the input file must first be sorted by STRATUM and PSU
 variables.)

      PROC ...  DESIGN = WR;
      NEST      STRATUM PSU;
      WEIGHT    WTF;

 See the Section "Worked SUDAAN Examples" for further discussion.


 CAUTION.  Method 2 should only be used on a full sample person data base.
 Using this method with subsetted data may lead to incorrectly computed
 standard errors.  (See the section "Subsetted Data Analysis" below).  If
 using a subsetted data set, the user should check the degree of agreement
 of the certainty and non-certainty counts with the values presented above.

 CAUTION
 A typically used rule-of-thumb for degrees of freedom to associate with a
 standard error is the quantity (number of PSUs - number of strata).  This
 rule assumes that the PSUs are somewhat comparable in size.  For Method 2
 this rule may be grossly inaccurate since the concept of PSU is quite
 different for certainty and non-certainty strata.  Certainty strata PSUs of
 Method 2 have small weighted values relative to those of non-certainty PSUs.
 The rule-of-thumb degrees of freedom for Method 1 is 187, and Method 2 should
 have a "true" degrees of freedom exceeding that of Method 1.  However, for
 practical purposes, any degrees of freedom exceeding 120 can be treated as
 infinite, i.e., one uses a normal Z-statistic instead of a t-statistic for
 testing.  Note, that a one-tailed critical t0.025 at 120 degrees of freedom
 is 1.98 while at an infinite degrees of freedom (i.e., a z-value) is 1.96.
 If a variable of interest covers most of the NHIS PSUs, the limiting value
 would probably be adequate for analysis.  The user should consult a
 mathematical statistician for discussion of degrees of freedom.

 SUBSETTED DATA ANALYSES

 Frequently, studies of NHIS variables are restricted to select subdomains,
 e.g., persons aged 65 and older.  To save on storage the user may delete all
 records outside of the domain of interest.  This procedure of keeping only
 select records is called subsetting the data.  With a subsetted data set one
 can produce correct point estimates, e.g., the subdomain means, but standard
 errors may be computed incorrectly when using a compromised design structure.
 For example, if a stratum of Method 2 contains 10 PSUs and 5 are lost because
 of subsetting, a SUDAAN run on the subsetted data will use an incorrect
 formula to compute stratum contributions to the variance.  If the full data
 are run, SUDAAN correctly handles the 5 empty PSUs.  Note, that SUDAAN has a
 SUBPOPN option that allows the targeting of a subdomain from a full design
 data base. (See the SUDAAN manual for details).

 Subsetting methods with SUDAAN

 Strategy 1.  Use Method 1 above with the MISSUNIT option on the NEST
 statement -
         NEST        STRATUM PSU/MISSUNIT ;
 If a WR design has exactly 2 PSUs per stratum and some PSUs are removed from
 the database then the SUDAAN MISSUNIT option performs a fix-up which produces
 a standard error identical to that achieved when using a full data set and
 SUBPOPN statement.  Note, other output like design effects, degrees of
 freedom, standardization may be computed differently.  The user is
 responsible for checking that subsetted input leads to correct results.

 Strategy 2.  Use Method 1 or 2 above on a "fixed-up" subsetted data set.
 Basically, one needs to add some dummy records containing full design
 information to the subsetted data set.  To do this follow these instructions:

 1. Create a 2-variable file containing STRATUM and PSU for each record of the
    full person file ( 100,000+ records )

 2. Sort this file by STRATUM and PSU within STRATUM.

 3. Keep only 1 record for each PSU
    add WTF = 10 -10  as a very small weight
    add variable DUMMY = 0  to designate dummy record

    A file, called DESIGN containing 4 variables with
     374 records ( Method 1 used) or with
    4338 records (Method 2 used) is created


 4. Append DESIGN to the original subsetted database, called DATASET, to form
 a new set, called   DATANEW.

        Define DUMMY = 1 on the DATASET component.

      On the DESIGN component records define all variables other than STRATUM,
  PSU, WTF, DUMMY   as missing ".".

 5. Sort DATANEW by STRATUM PSU

 6. In SUDAAN use a  "SUBPOPN  DUMMY = 1;" line to direct SUDAAN to restrict
 estimation to the subdomain of interest.

                                                                             
 With the above fix-up SUDAAN will correctly handle empty PSUs when computing
 the standard errors.  SUDAAN output that needs the entire full sample
 database for correct computation, e.g., design effects, may or may not be
 appropriate.  See the SUDAAN manual for computational forms or consult with
 a mathematical statistician for correct interpretation.

 Other notes on Subsetting data:

 If a subsetted database under Method 2 has only a few missing PSUs, the
 subsetted database can probably be run with SUDAAN without being fixed up.
 For example, a subsetting by SEX will most likely result in all PSUs still
 being in sample, but black males aged 65 and older would result in the loss
 of many PSUs.  The impact of running SUDAAN on uncorrected subsetted data
 varies.  Frequently, subsetted runs produce results consistent with those run
 on a full data set, but sometimes they do not.

 Subsetting by aggregates of Strata does not need a fix-up.

 The condition, doctor visit, and hospital record databases are actually
 subsetted files.  To use with SUDAAN properly, the information should be
 linked back to the appropriate person on the person file.  Some statistics,
 based upon aggregation of records, may be computed directly from this file
 along with the fix-up.  Consult with a statistician for appropriate SUDAAN
 usage.

 WORKED SUDAAN EXAMPLES

 In the following runs the variables used are

 LDR    = proportion of persons without a doctor visit in the last 2 years

 TDV_R  = mean number of annual doctor visits (based upon 2 week recall)

 HLT_FP = proportion of persons with self-reported fair or poor health status
          (omitting missing)

 AGE2: 1 = aged less than 18
       2 = aged 18 to 44
       3 = aged 45 to 64
       4 = aged 65 and older

 The following SUDAAN code was executed for both Method 1 and Method 2:

 Caution  The output presented below is based upon a preliminary NHIS Public
 Use database.  Your Public Use database may produce slightly different SUDAAN
 output.

    PROC DESCRIPT DATA = HIS.infile  FILETYPE=SAS DESIGN = WR;

    NEST       STRATUM PSU ;
    WEIGHT       WTF;

    VAR     LDR    TDV_R     HLT_FP ;

    SUBGROUP     SEX  AGE2;
    LEVELS       2    4;
    TABLES     SEX   AGE2;

    PRINT    NSUM WSUM MEAN SEMEAN
             / WSUMFMT=F10.0     MEANFMT=F8.5    SEMEANFMT=F8.5   ;


 Method 1: partial output:

                                   S U D A A N
             Software for the Statistical Analysis of Correlated Data
            Copyright      Research Triangle Institute      April 1996
                                   Release 7.00

 Number of observations read    : 102467    Weighted count :261889548
 Number of observations skipped :      0
 (WEIGHT variable nonpositive)
 Denominator degrees of freedom :    187

                              Research Triangle Institute

                                The DESCRIPT Procedure

 by: Variable, SEX.

 -----------------------------------------------------------------------------
 | Variable        |                  | SEX
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    0.13797 |    0.18013 |    0.09793 |
 |                 | SE Mean          |    0.00178 |    0.00250 |    0.00178 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    5.90759 |    4.90385 |    6.86089 |
 |                 | SE Mean          |    0.09060 |    0.10039 |    0.12407 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      48266 |      53011 |
 |                 | Weighted Size    |  258963568 |  126221708 |  132741859 |
 |                 | Mean             |    0.10126 |    0.09124 |    0.11079 |
 |                 | SE Mean          |    0.00157 |    0.00188 |    0.00176 |
 -----------------------------------------------------------------------------



 Method 1: partial output:

                                   S U D A A N
             Software for the Statistical Analysis of Correlated Data
            Copyright      Research Triangle Institute      April 1996
                                   Release 7.00

 Number of observations read    : 102467    Weighted count :261889548
 Number of observations skipped :      0
 (WEIGHT variable nonpositive)
 Denominator degrees of freedom :    187

                              Research Triangle Institute

                                The DESCRIPT Procedure

 by: Variable, AGE2.

 -----------------------------------------------------------------------------
 | Variable        |                  | AGE2
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    0.13797 |    0.08894 |    0.18489 |
 |                 | SE Mean          |    0.00178 |    0.00269 |    0.00268 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    5.90759 |    4.29682 |    4.88589 |
 |                 | SE Mean          |    0.09060 |    0.09797 |    0.12432 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      29183 |      40423 |
 |                 | Weighted Size    |  258963568 |   69438212 |  107054300 |
 |                 | Mean             |    0.10126 |    0.02552 |    0.06610 |
 |                 | SE Mean          |    0.00157 |    0.00129 |    0.00168 |
 -----------------------------------------------------------------------------
 ----------------------------------------------------------------
 | Variable        |                  |            |            |
 |                 |                  | 3          | 4          |
 ----------------------------------------------------------------
 | LDR             | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    0.14461 |    0.07606 |
 |                 | SE Mean          |    0.00293 |    0.00251 |
 ----------------------------------------------------------------
 | TDV_R           | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    7.08504 |   11.09843 |
 |                 | SE Mean          |    0.17859 |    0.30642 |
 ----------------------------------------------------------------
 |                 |                  |            |            |
 | HLT_FP          | Sample Size      |      19834 |      11837 |
 |                 | Weighted Size    |   51315866 |   31155190 |
 |                 | Mean             |    0.16651 |    0.28344 |
 |                 | SE Mean          |    0.00356 |    0.00519 |
 ----------------------------------------------------------------




 Method 2 Partial Output

                                   S U D A A N
             Software for the Statistical Analysis of Correlated Data
            Copyright      Research Triangle Institute      April 1996
                                   Release 7.00

 Number of observations read    : 102467    Weighted count :261889548
 Number of observations skipped :      0
 (WEIGHT variable nonpositive)
 Denominator degrees of freedom :   4030

                              Research Triangle Institute

                                The DESCRIPT Procedure

 by: Variable, SEX.

 -----------------------------------------------------------------------------
 | Variable        |                  | SEX
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    0.13797 |    0.18013 |    0.09793 |
 |                 | SE Mean          |    0.00174 |    0.00231 |    0.00184 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    5.90759 |    4.90385 |    6.86089 |

 |                 | SE Mean          |    0.07704 |    0.08503 |    0.11403 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      48266 |      53011 |
 |                 | Weighted Size    |  258963568 |  126221708 |  132741859 |
 |                 | Mean             |    0.10126 |    0.09124 |    0.11079 |
 |                 | SE Mean          |    0.00152 |    0.00174 |    0.00182 |
 -----------------------------------------------------------------------------


 Method 2 Partial Output

                                   S U D A A N
             Software for the Statistical Analysis of Correlated Data
            Copyright      Research Triangle Institute      April 1996
                                   Release 7.00

 Number of observations read    : 102467    Weighted count :261889548
 Number of observations skipped :      0
 (WEIGHT variable nonpositive)
 Denominator degrees of freedom :   4030

                              Research Triangle Institute

                                The DESCRIPT Procedure

 by: Variable, AGE2.

 -----------------------------------------------------------------------------
 | Variable        |                  | AGE2
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    0.13797 |    0.08894 |    0.18489 |
 |                 | SE Mean          |    0.00174 |    0.00271 |    0.00254 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    5.90759 |    4.29682 |    4.88589 |
 |                 | SE Mean          |    0.07704 |    0.09116 |    0.11805 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      29183 |      40423 |
 |                 | Weighted Size    |  258963568 |   69438212 |  107054300 |
 |                 | Mean             |    0.10126 |    0.02552 |    0.06610 |
 |                 | SE Mean          |    0.00152 |    0.00118 |    0.00157 |
 -----------------------------------------------------------------------------
 ----------------------------------------------------------------
 | Variable        |                  |
 |                 |                  | 3          | 4          |
 ----------------------------------------------------------------
 | LDR             | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    0.14461 |    0.07606 |
 |                 | SE Mean          |    0.00303 |    0.00269 |
 ----------------------------------------------------------------
 | TDV_R           | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    7.08504 |   11.09843 |
 |                 | SE Mean          |    0.16109 |    0.28387 |
 ----------------------------------------------------------------
 | HLT_FP          | Sample Size      |      19834 |      11837 |
 |                 | Weighted Size    |   51315866 |   31155190 |
 |                 | Mean             |    0.16651 |    0.28344 |
 |                 | SE Mean          |    0.00351 |    0.00501 |
 ----------------------------------------------------------------



 Best NHIS design using Durbin probabilities (not available to the public)
 and weights adjusted by post-stratification

 -----------------------------------------------------------------------------
 | Variable        |                  | SEX
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    0.13784 |    0.17991 |    0.09789 |
 |                 | SE Mean          |    0.00170 |    0.00221 |    0.00182 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      48809 |      53658 |
 |                 | Weighted Size    |  261889549 |  127570237 |  134319312 |
 |                 | Mean             |    5.90468 |    4.89733 |    6.86141 |
 |                 | SE Mean          |    0.07511 |    0.08320 |    0.11217 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      48266 |      53011 |
 |                 | Weighted Size    |  258974266 |  126232939 |  132741328 |
 |                 | Mean             |    0.10127 |    0.09125 |    0.11080 |
 |                 | SE Mean          |    0.00137 |    0.00159 |    0.00165 |
 -----------------------------------------------------------------------------



 Best NHIS design using Durbin probabilities (not available to the public)
 and weights adjusted by post-stratification

 Post-stratified estimates

 by: Variable, AGE2.

 -----------------------------------------------------------------------------
 | Variable        |                  | AGE2
 |                 |                  | Total      | 1          | 2          |
 -----------------------------------------------------------------------------
 | LDR             | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    0.13784 |    0.08845 |    0.18484 |
 |                 | SE Mean          |    0.00170 |    0.00258 |    0.00248 |
 -----------------------------------------------------------------------------
 | TDV_R           | Sample Size      |     102467 |      29711 |      40801 |
 |                 | Weighted Size    |  261889549 |   70670755 |  108040689 |
 |                 | Mean             |    5.90468 |    4.29787 |    4.87876 |
 |                 | SE Mean          |    0.07511 |    0.09066 |    0.11858 |
 -----------------------------------------------------------------------------
 | HLT_FP          | Sample Size      |     101277 |      29183 |      40423 |
 |                 | Weighted Size    |  258974266 |   69441900 |  107059972 |
 |                 | Mean             |    0.10127 |    0.02555 |    0.06624 |
 |                 | SE Mean          |    0.00137 |    0.00116 |    0.00153 |
 -----------------------------------------------------------------------------
 ----------------------------------------------------------------
 | Variable        |                  |
 |                 |                  | 3          | 4          |
 ----------------------------------------------------------------
 | LDR             | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    0.14484 |    0.07587 |
 |                 | SE Mean          |    0.00298 |    0.00268 |
 ----------------------------------------------------------------
 | TDV_R           | Sample Size      |      20000 |      11955 |
 |                 | Weighted Size    |   51713265 |   31464840 |
 |                 | Mean             |    7.08472 |   11.09687 |
 |                 | SE Mean          |    0.16180 |    0.27613 |
 ----------------------------------------------------------------
 | HLT_FP          | Sample Size      |      19834 |      11837 |
 |                 | Weighted Size    |   51315313 |   31157082 |
 |                 | Mean             |    0.16633 |    0.28322 |
 |                 | SE Mean          |    0.00342 |    0.00487 |
 ----------------------------------------------------------------



 Remark on Examples

 A comparison of the three SUDAAN examples shows that Method 2 performs quite
 well when compared to the "best" internal NCHS variance design for the NHIS.
 Based on limited preliminary evidence, it appears that for means, Method 2
 typically provides standard errors in close agreement with, while slightly
 larger than, the standard errors produced by the NCHS "best" method.  Method 1
 tends to provide slightly larger standard errors than Method 2 does, although
 the sample output does include examples where the Method 1 standard error is
 smaller than the Method 2 standard error.

 Reference:

 (1977)  Cochran, W. G., Sampling techniques (3rd ed), John Wiley & Sons



 Notes for Year 2000 application (added 01/21/98)

 The variance estimation methods of this document may be applied to the
 Year 2000 Objectives Public Use File.  The following changes must be made:

 The design information variables are all in the same file locations with the
 exception of "WTF".
 Substitute:

    WTF         207-212   'FINAL BASIC WEIGHT'

 The PSU check for method 2 should now read:

 As a check, the user should observe the following counts:

 Certainty Strata PSUs         3804
 Non-certainty Strata PSUs      259
 Total PSUs                    4063



 Notes on the 1996 NHIS (added 04/17/98)

 In 1996 the NHIS survey underwent a transition from a paper-and-pencil to a
 computer-assisted interview process.  This transition resulted in roughly
 5/8 of the available full sample being targeted for processing and public
 release.  In 1997 the full sample was again implemented.  For 1996 the reader
 should substitute the information on pages 3 and 4 and the top of page 5:

 Design Information Available on the NHIS Public Use Databases.

 Method 1 - 187 Strata containing 2 PSUs per stratum sampled with replacement

 Method 2 - Multiple PSUs per Stratum design sampled with replacement

 with the 1996 information on the following pages:


 Design Information Available on the 1996 NHIS Public Use Databases.

 The following variables are used to produce code for variance estimation.
 Field locations below are from the PERSON level database, but may change on
 other databases; the user should check the file documentation.

  Variable
   Name         Location      Field Label

  STRAT96*      354-357       'COLLAPSED VARIANCE STRATUM'

  PSU96*        358           'VARIANCE PSU'

  SUB_V         342-343       'SUBSTRATUM FOR VARIANCE ESTIMATION'

  SSU           344-350       'SECONDARY SAMPLING UNIT'

  PANEL         352           'PANEL 4'

  NSR96*        353           'NSR STATUS VARIABLE'

  WTF           219-227       'FINAL BASIC WEIGHT'

  (*indicates modified design variables added to the 1996 databases)


  Two methods of variance estimation are now provided.


  Method 1.96 -98 Strata containing 3 PSUs per stratum sampled with replacement

  Here, the NHIS universe has been partitioned into 98 collapsed strata with 3
  PSUs per stratum.  All PSUs are treated as sampled with replacement within
  their respective strata.  This method will provide somewhat conservative
  standard errors, and this standard error estimator itself has less stability
  than the standard error estimator described by Method 2.96 below.

  Coding required, (SAS  code provided):

         STRATUM = INT(STRAT96/10) * 10  ;

         PSU = PANEL ;

  Note, INT ( ) is the Integer-value SAS  function, e.g., INT(2.3) = 2

  As a check the user should observe 98*3 = 294 PSUs when using the full
  database.

  For the above simplification of the NHIS sample design structure, the
  following SUDAAN  design statements may be used.  (Note, the input file must
  first be sorted by STRATUM and PSU variables).


      PROC ... DESIGN = WR;
      NEST     STRATUM PSU ;
      WEIGHT   WTF;


  Method 2.96 - Multiple PSUs per Stratum design sampled with replacement

  This method provides for more statistically efficient variance estimation than
  Method 1.96, since it makes better use of the sampling design information.
  Its application is limited to software that can handle multiple PSUs per
  stratum, e.g., SUDAAN.  For this method the original certainty PSUs are
  partitioned by aggregations of the original race-ethnic density strata used in
  sampling.  The first randomly sampled unit is actually the SSU variable which
  is now treated as the PSU variable.  (Note, a certainty PSU unit contributes
  nothing to the variance at the PSU sampling level).  Non-certainty strata
  PSUs are treated as being sampled with replacement within their respective
  strata.


  Coding required (SAS  code provided):

  IF NSR96 = 1 THEN DO;  /*1996 certainty strata PSUs  */

       STRATUM  = STRAT96*100 + SUB_V;
          PSU    = SSU
          END;

  ELSE DO;              /* 1996 non-certainty PSU     */

     STRATUM = STRAT96 ;
       PSU     = PSU96   ;
       END;

  As a check, the user should observe the following counts:

  Certainty Strata PSUs         1736
  Non-certainty Strata PSUs      240
  Total PSUs                    1976

  For the Method 2.96 design structure, the following SUDAAN  design statements
  may be used.  (Note, the input file must first be sorted by STRATUM and PSU
  variables.)

      PROC ...  DESIGN = WR;
      NEST      STRATUM PSU ;
      WEIGHT    WTF ;

  Caution.  Both Method 1.96 and Method 2.96 should only be used on a full sample
  person database.  Using this method with subsetted data may lead to incorrectly
  computed standard errors.  (See the section Subsetted Data Analysis in the
  1995 section).  If using a subsetted data set, the user should check the degree
  of agreement in the PSU counts with the values presented above for either of
  the two methods.  Unlike Method 1 for 1995, Method 1.96 is not robust for
  analyzing subsetted survey data.

  CAUTION

  A typically used rule-of-thumb for degrees of freedom to associate with a
  standard error is the quantity (number of PSUs - number of strata).  This rule
  assumes that the PSUs are somewhat comparable in size.  For Method 2.96 this
  rule may be grossly inaccurate since the concept of PSU is quite different for
  certainty and non-certainty strata.  Certainty strata PSUs of Method 2.96 have
  small weighted values relative to those of non-certainty PSUs.  The rule-of-
  thumb degrees of freedom for Method 1.96 is 196, and Method 2.96 should
  have a true degrees of freedom exceeding that of Method 1.96.  However, for
  practical purposes, any degrees of freedom exceeding 120 can be treated as
  infinite, i.e., one uses a normal Z-statistic instead of a t-statistic for
  testing.  Note, that a one-tailed critical t0.025 at 120 degrees of freedom
  is 1.98 while at an infinite degrees of freedom (i.e., a z-value) is 1.96.  If
  a variable of interest covers most of the NHIS PSUs, the limiting value would
  probably be adequate for analysis.  The user should consult a mathematical
  statistican for discussion of degrees of freedom.

  The observant reader may notice that the 1996 method 1.96 has a larger rule of
  thumb degrees of freedom than the corresponding 1995 method 1.  The 1996
  variance estimation design consists of collapsed strata that may introduce a
  much larger stratum-collapse bias than occurred in 1995, and furthermore, the
  PSUs within each 1996 collapsed stratum have greater PSU weight diversity
  than in 1995 which may reduce stability.

  The section on SUBSETTED DATA ANALYSES in the 1995 section should be read
  considering the changes provided in this 1996 section.




This page last reviewed: Thursday, January 28, 2016
This information is provided as technical reference material. Please contact us at cwus@cdc.gov to request a simple text version of this document.
TOP