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Scientific Data Documentation
Epidemiologic Followup Study, 1992 Health Care Facility Stay
ACKNOWLEDGMENTS
Overall responsibility for the data processing and the compilation and
documentation for the NHANES I Epidemiologic Followup Study (NHEFS), 
1992 Health Care Facility Stay Public Use tape rested with 
Michael E. Mussolino.  Assistance was provided by other members of the 
NHEFS data management team: Sandra T. Rothwell, Christine S. Cox, 
Jennifer H. Madans, Dawn M. Scott, Madelyn A. Lane, Keith A. Zevallos, 
Joel C. Kleinman, Cynthia A. Reuben, Cordell W. Golden and Jacob J. Feldman.  
Special thanks are extended to Joan Cornoni-Huntley of the National 
Institute on Aging (NIA) who played an important role in the development 
and continuation of the NHEFS.  The contribution of Westat, the contractor 
who collected the data for this longitudinal study, is also gratefully 
acknowledged.
The NHEFS originated as a joint project between the National Center for 
Health Statistics (NCHS) and NIA.  It has been funded primarily by NIA, 
with additional financial support from the following components of the 
National Institutes of Health (NIH) and other Public Health Service agencies: 
the National Cancer Institute; the National Institute of Child Health and 
Human Development; the National Heart, Lung, and Blood Institute; the 
National Institute on Alcohol Abuse and Alcoholism; the National Institute 
of Mental Health; the National Institute of Diabetes and Digestive and 
Kidney Diseases; the National Institute of Arthritis and Musculoskeletal 
and Skin Diseases; the National Institute of Allergy and Infectious 
Diseases; and, the National Institute of Neurological and
Communicative Disorders and Stroke.
CONTENTS
                                                                     Page
Use of NHEFS Data....................................................   1
Errors in the Data Tapes and Survey Differences......................   2
NHANES I Epidemiologic Followup Study, 1992..........................   3
1992 NHEFS Health Care Facility Stay Data Tape Characteristics.......   8 
1992 NHEFS Health Care Facility Stay Introduction ...................   9
Medical Coding Specifications........................................  15
1992 NHEFS Health Care Facility Stay Public Use Tape Documentation...  21
Figure 1: Health Care Facility Record Layout.........................  43
Figure 2: Example of Matching Process and Record Status Codes........  44
Appendix A: Record Status Codes......................................  45
Appendix B: Numeric Codes for Reported Conditions....................  47
USE OF NHEFS DATA
With the goal of mutual benefit, NCHS requests the cooperation of recipients 
of data tapes in certain actions related to their use:
A.     Any published material derived from the data should acknowledge the
       National Center for Health Statistics (NCHS) as the original source. 
       It should also include a disclaimer which credits any analyses,
       interpretations, or conclusions reached to the author (recipient of 
       the tape) and not to NCHS, which is responsible only for the initial 
       data.
B.     Consumers who wish to publish a technical description of the data 
       will make a reasonable effort to insure that the description is not
       inconsistent with that published by NCHS.  This does not mean, 
       however, that NCHS will review such descriptions.
C.     Authors should provide NCHS with a reprint of published articles which
       utilize the 1992 NHEFS data.  Please send reprints to :  

            NHEFS Data Management Staff
            Division of Epidemiology
            National Center for Health Statistics 
            Presidential Building, Room 730
            6525 Belcrest Road
            Hyattsville, MD 20782
       

ERRORS IN THE DATA TAPES AND SURVEY DIFFERENCES
The NHEFS Public Use data tapes have been subjected to a great deal of 
careful editing.  However, due to the large volume of data in the series, 
it is likely that a small number of errors or discrepancies remain 
undetected.
In general, the NHEFS data management team has not attempted to resolve
substantive data discrepancies that may exist 1) within the 1992 NHEFS data
tapes, or 2) between the 1992 NHEFS data tapes and the data tapes of the 
original National Health and Nutrition Examination Survey (NHANES I) and 
other NHEFS followup waves. 
                      
NHANES I EPIDEMIOLOGIC FOLLOWUP STUDY, 1992
I. NHEFS BACKGROUND INFORMATION
The NHANES I Epidemiologic Followup Study (NHEFS) is a longitudinal study 
which uses as its baseline those adult persons ages 25 to 74 years who 
were examined in the first National Health and Nutrition Examination Survey 
(NHANES I).  The NHEFS is comprised of a series of four followup surveys.  
The first wave of data collection, the 1982-84 NHEFS, was conducted from 
1982 to 1984 and included all persons who were between 25 and 74 years at 
their NHANES I examination (n=14,407).  The second wave of data collection, 
the 1986 NHEFS, was conducted for members of the NHEFS cohort who were 
55-74 years at their baseline examination and not known to be deceased at 
the 1982-84 NHEFS (n=3,980).  The third wave of data collection, the 1987 
NHEFS, was conducted for the entire non-deceased NHEFS cohort (n=11,750).  
The fourth wave of data collection, the 1992 NHEFS, was also conducted for 
the entire non-deceased NHEFS cohort (n=11,195). This series of file 
documentation describes data collected in the 1992 NHEFS.  
NHANES I collected data from a national probability sample of the United 
States civilian noninstitutionalized population between the ages of 1 and 74 
years.  The survey, which included a standardized medical examination and 
questionnaires that covered various health-related topics, took place from 
1971 through 1974 and was augmented by an additional national sample in 
1974-75.  The NHANES I sample included 20,729 persons 25 to 74 years of age, 
of whom 14,407 (70 percent) completed a medical examination. The design, 
content and operation of NHANES I has been described elsewhere (Vital and 
Health Statistics, Series 1, Nos. 10a, 10b, and 14).
Although NHANES I provided a wealth of information on the prevalence of health
conditions and risk factors, the cross-sectional nature of the original survey
limits its usefulness for studying the effects of clinical, environmental, and
behavioral factors and in tracing the natural history of disease.  Therefore, the
NHEFS was designed to investigate the association between factors measured at the
baseline and the development of specific health conditions.  It originated as a
joint project between the National Center for Health Statistics (NCHS) and the
National Institute on Aging with collaboration from components of the National
Institutes of Health and other Public Health Service agencies.  The 14,407
participants who were 25 to 74 years of age when they were examined in NHANES I
(1971-75) were included in the followup study population.
In the first wave, the 1982-84 NHEFS, data were collected on all 14,407 subjects
(i.e., individuals examined at NHANES I) in the cohort.  Tracing of subjects
began in 1981 and data collection was conducted from 1982 to 1984.  Approximately
93 percent (n=13,383) of the cohort was successfully traced by the end of the
survey period.  Detailed information on the design, content, and operation of the
1982-84 NHEFS may be found in the Plan and Operation of the NHANES I
Epidemiologic Followup Study 1982-84, Vital and Health Statistics, Series 1, No.
22.  The basic design of the 1982-84 NHEFS consisted of the following components:
              --   tracing subjects or their proxies to a current address;
              --   acquiring death certificates for deceased subjects;
              --   performing in-depth interviews with the subjects or with their
                   proxies including, for surviving subjects, taking pulse, blood
                   pressure, and weight measurements of subjects; and,
              --   obtaining hospital and nursing home records, including pathology
                   reports and electrocardiograms.
The second wave of the NHEFS, the 1986 NHEFS, was conducted to assess changes in
the health and functional status of the oldest members of the NHEFS cohort since
the last contact period.  It included 5,677 subjects who were 55 years or older
at their NHANES I examination (almost 40 percent of the entire NHEFS cohort). 
Data collection was restricted to 3,980 subjects aged 55 years or older at NHANES
I who were not known to be deceased at the time of the 1982-84 NHEFS, regardless
of their tracing or interview status in 1982-84.  The remaining 1,697 subjects
who were deceased at the time of the 1982-84 NHEFS were excluded from additional
data collection in the 1986 NHEFS.  Detailed information on the design, content,
and operation of the 1986 NHEFS may be found in the Plan and Operation of the
NHANES I Epidemiologic Followup Study 1986, Vital and Health Statistics, Series
1, No. 25.
The 1987 NHEFS, the third wave of the NHEFS, was designed to collect information
on changes in the health and functional status of the NHEFS cohort since the last
contact period.  Tracing and data collection were conducted during this followup
survey only for the members of the NHEFS cohort who had not been identified as
deceased in 1982-84 or 1986 (n=11,750) regardless of their previous tracing or
interview status.  The 2,657 previously deceased subjects were excluded from
additional data collection in the 1987 NHEFS.  Detailed information on the
design, content and operation of the 1987 NHEFS may be found in the Plan and
Operation of the NHANES I Epidemiologic Followup Study 1987,  Vital and Health
Statistics, Series 1, No. 27.
The fourth wave of NHEFS, the 1992 NHEFS, collected information on changes in the
health and functional status of the NHEFS cohort since the last contact period. 
Tracing and data collection were conducted during this followup survey only for
the members of the NHEFS cohort who had not been identified as deceased in 1982-
84, 1986 or 1987 (n=11,195) regardless of their previous tracing or interview
status.  The 3,212 previously deceased subjects were excluded from additional
data collection in the 1992 NHEFS. 
The design and data collection procedures adopted in the 1992 NHEFS were very
similar to the ones developed in the previous surveys: subjects were traced;
subject and proxy interviews were conducted; and, health care facility abstracts
and death certificates were collected.  All subjects whose vital status was not
obtained through tracing procedures were considered lost-to-followup in the 1992
NHEFS.  In some cases, information about the death of a subject was obtained from
a former neighbor, a relative or another tracing source.  Although this
information was noted in the subject's tracing record, he or she was considered
lost-to-followup unless the information was verified by means of a death
certificate or proxy interview.  A subject's death had to be confirmed by either
a death certificate or proxy interview.  
In addition to verifying the subject's vital status, the tracing process also was
used to obtain the current address of surviving subjects as well as to identify
a knowledgeable proxy respondent for deceased subjects.  Respondents who were
identified and located through the tracing procedures were asked to participate
in a telephone interview.  In a few cases, subjects who had been traced
successfully could not be relocated for the interview.  Only their vital status
and the date when they were last traced in the 1992 survey are available.
A major difference between the 1982-84 and 1992 NHEFS waves was the manner in
which the interviews were conducted.  In the 1982-84 NHEFS, the two-hour subject
interview was usually conducted in-person while, in subsequent followups the
interview was shortened to approximately 30 minutes in length and was conducted
primarily by telephone.  In addition, since the questionnaire was not
administered in-person, no physical measurements were made in the 1986, 1987 or
the 1992 NHEFS.
The 1992 NHEFS interviews were conducted over the telephone using a Computer
Assisted Telephone Interviewing (CATI) system.  CATI is a telephone interviewing
technique that allows the interviewer to enter the answers supplied by the
respondent directly into the computer.  Thus, editing and coding time is reduced
and keypunching from a hard copy questionnaire is eliminated.  A computer program
drives the questionnaire so that the correct skip patterns are followed and the
appropriate questions are displayed on the computer monitor.  The skip patterns
are based on information gathered from previous data collection waves or on
responses provided during the 1992 interview.  For example, certain questions on
pregnancy and menstrual history in the 1992 interview were programmed to be
skipped automatically if the subject was male or if the female subject was
interviewed previously and was 45 years of age or older at the time of that
interview.  Edit and logic checks are incorporated into the data collection
system itself, thus improving the quality of the data.
As of July 19, 1993, the end of the 1992 NHEFS data collection period, 10,079
(90.0 percent) of the 11,195 members of the 1992 NHEFS cohort had been
successfully traced.  Interviews were conducted for 9,281 subjects (92.1 percent
of those successfully traced).  In addition, 10,535 facility stay records were
collected for 4,162 subjects using information obtained from the interview, death
certificate, or some other source.  Death certificates were obtained for 1,374
(98.7 percent) of the 1,392 subjects who were known to have died since last
contact.  Detailed information on the design, content, and operation of the 1992
NHEFS may be found in the Plan and Operation of the NHANES I Epidemiologic
Followup Study 1992, Vital and Health Statistics, Series 1, No. 35.
The data collected from the 1992 NHEFS are stored on four separate tapes:
                   1)   Vital and Tracing Status tape -- contains summary information
            about the status of the cohort, 
                   2)   Interview tape -- contains the data collected from the 1992
            NHEFS subject and proxy interviews,
       
                   3)   Mortality Data tape  -- contains data abstracted from the death
            certificates from all three NHEFS surveys,
       
                   4)   Health Care Facility Stay tape -- contains information on
            reports of stays in hospitals and non-hospital health care
            facilities (e.g., nursing home, mental health care facility) as
            well as information abstracted from facility medical records. 
            This tape is described in detail in the following pages. 
              
1992 NHEFS HEALTH CARE FACILITY STAY DATA TAPE CHARACTERISTICS

Title:                  1992 NHEFS Health Care Facility Stay Data Tape
Data Set Name:          NHEFS4.HCFS.FINAL
Record Length:          429
Blocksize:              31746
Number of Records: 10,535
Recording/
Storage Media:          FIXED BLOCK, EBCDIC/IBM 3480 Cartridge Tape
Created by:             Office of Analysis, Epidemiology and Health Promotion
                                                Division of Epidemiology
                                                National Center for Health Statistics
                                                Presidential Building, Room 730
                                                6525 Belcrest Road
                                                Hyattsville, Maryland  20782
1992 NHEFS HEALTH CARE FACILITY STAY INTRODUCTION
The 1992 NHEFS Health Care Facility Stay (HCFS) file contains information on all
overnight health care facility stays for members of the 1992 Followup cohort. 
The 1992 Followup cohort consisted of the 11,195 subjects who were between 25 and
74 years old at their NHANES I examination and were not known to be deceased at
the time of the 1987 NHEFS.  Followup cohort members who have either an interview
or a death certificate on the 1992 NHEFS data files were eligible for the health
care facility records component.  The aim of this component was to develop a
complete set of health care facility (i.e., hospital and nursing home) records
for each 1992 Followup cohort member.  This was accomplished by identifying all
facility stays through a series of reporting mechanisms.  Facilities were
contacted to obtain copies of medical records.  Reports and medical records were
then linked and the 1992 NHEFS Health Care Facility Stay file was constructed. 
The procedures for obtaining reports and collecting abstracts are described
briefly, below.  
The 1992 NHEFS Health Care Facility Stay file contains all information on
overnight stays that are in-scope for the 1992 NHEFS period.  The in-scope period
depends upon the timing of the subject's last interview and his/her vital status. 
For subjects who have not been interviewed since the NHANES I exam, the 1992 in-
scope period is from the date of the NHANES I exam to the date of the 1992
interview for surviving subjects and from the exam date to the date of death for
deceased subjects.  For subjects who have had at least one followup interview
prior to the 1992 followup, the in-scope period is from the date of the last
interview (either 1982-84, 1986 or 1987) to the date of the 1992 interview for
surviving subjects and from the date of the last interview to the date of death
for deceased subjects.  Stays that were reported prior to the in-scope period
were defined as out-of-scope for the 1992 survey.

Identification of Stay Reports:    
Reports of overnight hospital or nursing home facility stays were obtained from
various sources.  Most reports were elicited through a series of detailed
questions in section B of the interview.  Generally, respondents were asked to
report all overnight facility stays since 1987 if the subject was last
interviewed in the 1987 NHEFS, since 1985 if the subject was last interviewed in
the 1986 NHEFS, since 1980 if the subject was last interviewed in the 1982-84
NHEFS, or since 1970 if the subject was last interviewed at NHANES I examination. 
In addition to interview information, data on facility stays were gathered from
other reporting sources:  from the death certificate, tracing sources, and other
hospital abstracts.  At the conclusion of the interview, authorization was
obtained for permission to contact facilities.  
Facility Data Collection:
For each stay reported during the interview, the name and address of the
facility, the reported dates of the stay, and the reason for the stay were
recorded on the hospital and health care facility chart (HHCF).   A separate log
book was kept containing similar data for reports gathered from the death
certificates, tracing sources, and other hospital abstracts.  All reports of
facility stays were compiled and entered into a computerized tracking system. 
All reported facilities were contacted by mail and asked to review the subject's
medical records and to abstract information on exact dates of admission,
discharge and diagnoses onto standard abstract forms.  In addition to completing
abstract forms, facilities were requested to submit photocopies of selected
sections of the subject's inpatient record i.e., the "facesheet", the discharge
summary and of pathology reports (for any admission where a new malignancy was
diagnosed).  
Matching Records:
As the abstracts were received, they were checked against report information in
the tracking system to determine if the abstract "matched" any of the reported
stays.  Date of admission and diagnosis were used as matching criteria but exact
matches on date or diagnosis were not required for a stay to be considered
matched.  Abstracts were matched to reports if the reported date of admission was
within a year of the actual date of admission and if the reported reason for
admission involved the same body system as at least one of the diagnoses present
on the abstract.  Cases that did not meet these specific criteria were reviewed
by NCHS staff and matched when appropriate.  Since the matching rules allowed for
an admission date of up to one year before or after the reported date of
admission, some stay records are present on the file with a match record status,
an out-of-scope report date, but an in-scope date on the abstract.  These records
are identified by a Type C flag in position 199 of the file.   
Each record on the file represents an overnight facility stay.  Therefore, one
or more records will exist for some 1992 Followup cohort subjects, while other
subjects will have no records on the file.  The structure of the data file
reflects the system used to obtain and process stay information.  The record is
divided into four major sections:  1) the report section,  2) the record status
section, 3) the abstract section, and 4) the related stay section.  An example
of the record layout is provided in figure 1.  
The subject identification number (i.e. the sample sequence number) is in
positions 1-5 on each record.  This number is unique for each subject and is used
when linking the Health Care Facility Stay tape to all other NHEFS and NHANES I
Public Use Data Tapes.  The total number of records per subject is found in
positions 6-7 on the file.  The first section of the record is the report section
(positions 29-59 and 63-204) which contains information from the reporting source
as well as stay identification numbers assigned by NCHS.  Each stay entered into
the report section is assigned a health care facility stay ID number (positions
29-33).  When used in conjunction with the sample sequence number, this number
uniquely identifies each record on the file.  The reported date of admission is
found in positions 47-54.  This date is used in conjunction with the last
interview date to determine whether reported stays were in-scope for the NHEFS
1992 survey (position 199).  
The record status section (positions 60-62) contains a code for the result of the
abstract request, i.e. match or non-match status.  If a facility returned an
abstract that matched a report then a record status code of MAT (match) was
applied.  A returned abstract that did not match a report but was in-scope for
the 1992 survey period was assigned the record status code of ASF (additional
stay found).  A record status code of CRM (cross-referenced match) was applied
to a stay that was the continuation of a stay begun prior to the 1992 NHEFS
survey period.  If an abstract was not returned, the appropriate non-match code
was assigned.  
The abstract section (positions 205-379) contains the information obtained from
the facility records including actual dates of admission, discharge and
diagnoses.  The diagnoses on the abstracts were coded using the ICD-9-CM
according to the medical coding specifications detailed in the following section
of this codebook.  The abstract section is similar to the original 1982-84 NHEFS
Health Care Facility record file released in August 1987.  The other three
sections were added when the 1986 version of the Health Care Facility Stay file
was designed.  A revised 1982-84 HCFS data tape which is structured in the same
format as the 1986, 1987 and 1992 HCFS tapes has also been released. 
Information will be present in one or more sections of the record depending on
whether a report was obtained, and whether an abstract was received.  The
presence or absence of information in the first three sections results in three
different record profiles.  Figure 2 illustrates these three profiles.  The first
is the successfully matched stay record, where an abstract was received which
matched a report.  Abstract information is added to the report and the code of
MAT was entered into the record status section.  Complete information is
available in the first three sections of the record for these stays.  The second
type occurs when an abstract was not matched to a report and, therefore, no data
is contained in the abstract section.  The appropriate non-match code was entered
in the record status section.  The third type of record is one which was
generated solely by the receipt of a facility abstract.  This type of record
resulted when the facility returned an in-scope abstract that did not match with
any report on the tracking system.  When this occurred, the abstract was entered
on the file, and stay identifiers were assigned in the report section of the
record but no other information in the report section is present.  An ASF
(additional stay found) code was entered in the record status section.  
In some cases requests were made to facilities for information about stays with
reported admission dates that preceded the date of the NHANES I exam (i.e., were
out-of-scope).  This was done to maximize the collection of reports of hospital
or nursing home stays.  Reports of stays with a reported date of admission more
than one year prior to the exam were retained on the file when they represented
the only mention of visits to a specific health care facility for a given
subject.  These were flagged with a Type D in Position 199.  All stays with
reported dates within the year immediately preceding the exam were kept and
flagged with a Type C in position 199.
After the receipt of information from the health care facility, it was necessary
to remove stays from the tracking system that had been out-of-scope and to
incorporate information on in-scope stays that was generated from the "out-of-
scope" reports.  If an in-scope abstract was received from a facility named on
a Type D report, the in-scope stay was added to the file with a record status
code of ASF and the Type D report was deleted from the file.  The Type D report
was also deleted from the file if the facility responded to the Type D request,
but sent no in-scope abstracts.  In this case it was presumed that the respondent
had correctly reported the date as out-of-scope.  One Type D report remains on
the final version of the file.  This occurred because it was impossible to
contact the facility.  These records for unconfirmed reports of out-of-scope
stays can be eliminated from analyses at the analysts' discretion.  In the case
of Type C reports, if an in-scope abstract was returned which matched the Type
C report, the report was assigned a record status code of MAT (n=12).  (Recall
that matching rules permitted an admission date of up to one year before or after
the reported date of admission).  If the facility responded but no in-scope
abstract was received, the Type C report was also removed from the file.  Again
it was assumed that the correct date had been reported and the stay was truly
out-of-scope.  There are 12 Type C reports that remain on the file.  These
reports were given by respondents who did not grant permission to obtain
abstracts or they involved facilities that could not be contacted, refused to
participate or did not respond.  These unconfirmed reports of out-of-scope stays
are identified by the non-match status in positions 60-62 and a Type C flag in
position 199.
The final section of the record contains related stay codes (positions 380-429). 
These related stay codes are used to identify stays which are contained within
other stays.  This occurred most often when nursing home residents had a brief
hospital stay but then returned to the nursing home.  A detailed example of the
related stay section is presented below.  In panel A, a chronological history of
a subject's hospital and nursing home stays is presented in order to facilitate
the discussion of the related stay codes.  This subject was admitted to the
nursing home on March 1, 1989, and discharged to the hospital on April 1, 1989. 
He returned to the original nursing home on April 8 and stayed until April 22
when he required readmission to the hospital.  He returned from the hospital to
the nursing home on April 25, 1989 where he remained until April 30, 1989.
Panel A:  Chronological profile of hospital and nursing home stays: 
Location                  Admission           Discharge 
Nursing home              03/01/89            04/01/89
Hospital                  04/01/89            04/08/89
Nursing home              04/08/89            04/22/89
Hospital                  04/22/89            04/25/89
Nursing home              04/25/89            04/30/89
Panel B illustrates how these stays are present in the final file.  The three
nursing home stays were collapsed into one long stay with two related
hospitalizations.  The related stay codes were added to demonstrate the
relationship between the hospital and nursing home stays.
Panel B:  Final file layout
Variable Position:
29-33 209       210-215   216-221   380-384   385-389
Variable Name:
Stay                      Dis-      First     Second
Number          Type      Admit     charge    Related   Related
40201 N. Home   03/01/89  04/30/89  40101     40102 
40101 Hosp      04/01/89  04/08/89  40201
40102 Hosp      04/22/89  04/25/89  40201 
MEDICAL CODING SPECIFICATIONS
Medical coding for the NHEFS 1992 data tape was based on the International
Classification of Diseases-9th Revision-Clinical Modification (ICD-9-CM). The
health care facility was asked to abstract all diagnoses and procedures onto a
special form.  In most cases, a copy of the hospital discharge summary and/or
medical records facesheet was attached to the abstract.  The diagnoses and
procedures listed on the discharge summary or facesheet were then compared with
those provided on the abstract form.   In most instances, discrepancies were
resolved by coding the diagnoses or procedures as provided on the discharge
summary or the facesheet.
All diagnoses were coded to the highest level of specificity possible.  The
fourth-digit subcategory for diagnosis and procedure codes was used whenever
possible.  The fifth-digit subclassification of disease for diagnosis codes was
also used when appropriate.  A three-digit ICD code was used only if it could not
be further subdivided.  The following rules were used to code diagnoses and
procedures.
 
Rules Governing Medical Coding of Diagnoses:
All medical diagnoses listed on the health care facility abstract form or the
discharge summary are coded by trained medical coders.  The coders assigned the 
principal diagnosis as the condition established after study to be chiefly
responsible for occasioning the admission of the patient to the health care
facility.  The admitting diagnosis is not used as the principal diagnosis unless
the admitting and discharge diagnoses are the same.

      Ex:  Patient admitted with a diagnosis of bronchopneumonia. After workup
      and treatment, x-ray findings, etc., the patient was discharged with a
      final diagnosis of bronchopneumonia. The principal diagnosis is coded
      485 for bronchopneumonia.
All other diagnoses or conditions existing at the time of admission or that
developed subsequently during the stay are coded.  

      Ex:  Patient was admitted with a diagnosis of uncontrolled diabetes
      mellitus, and during the course of examination and treatment, phlebitis
      was discovered.  The diabetes and the phlebitis are coded.
Diagnoses documented as probable, possible, suspected, question of, suggestive
of, compatible with, or questionable are coded and prefixed with a "P".

      Ex:  If the diagnosis is stated possible myocardial infarction, the
      diagnosis code is P410.9.
If a diagnosis is stated as "rule out" or "R/O", the condition is coded as if it
exists and the "P" prefix is not used.  If a diagnosis is stated as "ruled out",
the condition is not coded.

      Ex:  If "R/O M.I." appears on the facesheet, the code is 410.9
           If "M.I. ruled out" appears, the condition is not coded.  
Hospital acquired infections, such as a "staph" infection, if documented on the
facesheet and/or discharge summary are coded.  Documentation may be in the form
of a note by the infections committee, stamped notation, or a checkmark,
depending on the record format.
Malignant neoplasms are coded according to ICD-9-CM coding specifications which
indicate primary site of origin.
Injuries and poisonings are coded, where applicable, using both the nature of the
injury and the external cause of injury code (E800-E999).

      Ex:  Patient sustained comminuted fracture of the femur due to a fall
      down stairs.  Nature of injury code is 821.00 and external cause of
      injury code is E880.9
"History of" conditions are not coded with the following exceptions:
      Old myocardial infarction (more than 8 weeks since last occurrence)
            Status post bypass surgery
            Malignant neoplasm (cancer in remission or under treatment)
      Old cerebrovascular accident
            Sterilization
            Normal pregnancy undelivered
            Manipulation of an IUD
These diagnoses are coded using "V" codes and were used on a limited basis.  
Recurrent malignancy codes are prefixed with an "R".
Symptoms (ICD-9-CM codes 7800-7999) were coded using the following  guidelines:
     1.   When the only diagnosis listed on the abstract form, facesheet, and/or
          discharge summary is a symptom, the symptom is coded.
          Ex:  The only discharge diagnosis listed is "chest pain".  The code
          number 786.50 (chest pain, unspecified) is assigned.
     2.   When a symptom is listed that is unrelated to any of the diagnoses
          listed, the symptom is coded.
          Ex:  The discharge diagnoses listed are acute myocardial infarction,
          diabetes mellitus, and hepatomegaly.  The hepatomegaly is also coded.
     3.   When a symptom is listed and is related to a listed discharge diagnosis
          the symptom is not coded.
          Ex:  The discharge diagnoses listed are diabetes mellitus, acute
          appendicitis, severe abdominal pain.  Only the diabetes and the
          appendicitis are coded.  The abdominal pain is not coded. 
Rules Governing Medical Codes for Procedures:
The same general rules apply to coding procedures as to coding diagnoses. Medical
procedures are coded by trained medical coders from the information described on
the health care facility abstract form or the discharge summary/facesheet.
The principal procedure is the primary procedure most related to the principal
diagnosis and is performed for definitive treatment as opposed to diagnostic
and/or exploratory purposes.
 
           Ex:  Diagnosis  = uterine fibroids.
           Procedures = biopsy of uterus, total abdominal hysterectomy,
           incidental appendectomy.
           The hysterectomy is coded as the principal procedure and the
           appendectomy and the biopsy are coded as secondary procedures.  
All procedures documented on the discharge summary and/or facesheet are coded if
they fall into the following categories:

      Biopsies (if related to the principal diagnosis and procedure or if
      related to other listed diagnoses)
  
            Surgical procedures
            Cardiac catheterizations
            D and C (following delivery or abortion only)
The following procedures are not coded:
            Surgical approach
            Operative cholangiogram
            Lumbar puncture
            CT scan
            Endoscopy
            Diagnostic D and C
            Diagnostic radiology
            Examination (under anesthesia, physical exam, etc.)
            Manipulations
            Physical therapy
            Application or removal of casts, splints, etc.

Medical Coding Conventions:
Diagnostic codes--Up to ten diagnoses are coded for each hospital and nursing
home stay.  The format for each diagnosis code is six positions.  The following
conventions were used when entering diagnostic codes on the data tape:
 1.   ICD-9-CM diagnostic codes (including "V" codes) were entered beginning
      with the second position of the variable field continuing through the
      sixth position.  There is an implied decimal point between the fourth
      and fifth positions of the variable field.
 2.   If the diagnoses code required less than five digits the remaining tape
      positions are blank.
 3.   Prefix codes "P" and "R" are coded in the first tape position. If the
      diagnosis code has no prefix the first position is blank.
                      Ex. 1:  _ 4 2 2 9 0    Code is 422.90
                 Ex. 2:  _ V 7 1 1 _    Code is V71.1
                 Ex. 3:  _ 4 3 6 _ _    Code is 436
                 Ex. 4:  P 1 8 0 0 _    Code is P180.0
                 Ex. 5:  R 1 7 4 9 _    Code is R174.9
 4.   E codes - External cause of injury codes
      An external cause of injury code is provided, when applicable, 
      immediately after the medical diagnosis code which describes the nature
      of the injury.  E codes were entered on the data tape beginning in the
      first position of the variable field and continuing through the fifth
      position.  There is an implied decimal point between the fourth and
      fifth positions of the variable field.  If an E code required less than
      five positions the remaining positions are blank.  If an E code is not
      applicable (i.e.  the medical diagnosis code is not a nature of injury
      code)  or could not be coded, the variable field is blank.
                      Ex. 1:  E 9 0 6 1      Code is E906.1
                      Ex. 2:  E 8 5 1 _      Code is E851
Procedure codes--Up to five procedures are coded for each health care facility
record.  Each procedure code is formatted in a field containing four positions.
Procedure codes were entered beginning with the first position of the variable
field continuing through the fourth position.  There is an implied decimal point
between the second and third positions of the variable field.  If a procedure
code required less than four positions the remaining positions are blank.
                      Ex. 1:  4 2 9 2      Code is 42.92
                      Ex. 2:  0 3 1 _      Code is 03.1
    
SUBJECT INFORMATION
     
     1-5                    10535 NHANES I Sample Sequence Number
     
     6-7                          Record Count
     
                            10535 01-30 = Total number of records
     
                                  Note:  Each record on the file represents
                                  an overnight stay in a health care facility
                                  (hospital or nursing home).  This variable
                                  identifies for each subject the total
                                  number of records on the file.  It will be
                                  the same for each record the subject has on
                                  the file.
     
     8-28                   10535 Blank
     
                                  STAY IDENTIFIERS AND REPORTED INFORMATION
                                  ON FACILITY STAYS
     
                                  Note:  The report section of the record
                                  (positions 29-59 and 63-204) contains the
                                  information on health care facility stays
                                  that was reported on the questionnaire, on
                                  a death certificate, on another
                                  hospital/nursing home abstract form, or
                                  obtained from other sources.
     
     (29-33)                      Health Care Facility Stay ID Number
     
                                  Note:  When used in conjunction with the
                                  sample sequence number this number uniquely
                                  identifies each record on the tape.  It is
                                  composed of three variables:  Survey Period
                                  Identifier, Facility Number and Stay Number
                                  Within Facility.  For example: a Stay
                                  Number of 40102 refers to a facility stay
                                  reported during the NHEFS 1992 wave (4) in
                                  the first facility reported for that
                                  subject (01) and the second admission to
                                  that facility (02).
     
     29                           Survey Period Identifier
     
                            10535 4 = NHEFS 1992
     
                                  Note:  This variable identifies the survey
                                  period in which the stay data were
                                  collected.  A facility stay reported during
                                  the NHEFS 1992 wave will be identified with
                                  a code number "4".  All records on this
                                  file are coded "4" in this field.
     
     30-31                        Facility Number
     
                            10535 01-91 = Hospital/nursing home number
     
                                  Note:  For each NHEFS subject, a two digit
                                  number was assigned to each facility in
                                  which a stay occurred.  Thus, if a subject
                                  had multiple stays at the same facility,
                                  all stays will have the same facility
                                  number.
     
                                  Facility numbers were assigned
                                  consecutively.  However, due to tape
                                  editing, there are missing numbers in the
                                  sequence of facility numbers.
     
     32-33                        Stay Number Within Facility
     
                   10534          01-25 = Stay number
                                  1 00  = D stay record
     
                                                                                             Note:  The two digit stay numbers were
                                  assigned to identify different stays in the
                                  same facility.  Type D stay records were
                                  assigned a stay number of "00".  A type D
                                  stay record is defined as a stay with a
                                  reported admission date more than one year
                                  prior to the date of last interview (see
                                  position 199).
     
                                  Stay numbers within facilities were
                                  assigned consecutively.  However, due to
                                  tape editing, there are missing numbers in
                                  the sequence of stay numbers within
                                  facilities.
     
     34-35                                  Facility ID Prefix
      
                                        9337     01 = Hospital
                                        1108     02 = Nursing Home
                                          90     03 = Out of country, don't know, not 
                                                     ascertained
     
                                   Note:  This variable identifies the type of
                                   facility to which the request for a stay
                                   record was mailed.
     
     36-46                             10535    Blank
     
     (47-54)                       Reported Admission Date/Range
     
                                   The date of admission to a facility is
                                   reported by month, day and year.  A range
                                   of years was coded when the respondent was
                                   unable to recall the exact year of
                                   admission.  When the year of admission was
                                   reported as a range, the beginning year of
                                   the range is found in positions 51-52 and
                                   the ending year of the range is found in
                                   positions 53-54.  Except for type D
                                   (position 199) records the reported date of
                                   admission is present for all source code 2
                                   and 4 records (see position 200), and CRM
                                   and CRX records (positions 60-62).
     
     47-48                        Reported Month of Admission
     
                                        6764    01-12 = Month of admission
                             1340 98    = Don't know
                              248 99    = Not ascertained
                            2183  Blank = Type D (position 199), or record 
                                   status code ASF (positions 60-62),
                                   or source code 1 or 3 (position
                                   200) and record status code
                                   (positions 60-62) not a cross-
                                   referenced stay (CRM, CRX)
     
     49-50                        Reported Day of Admission
     
                             4153 01-31 = Day of admission
                             3951 98    = Don't know
                              248 99    = Not ascertained
                             2183 Blank = Type D (position 199), or record
                                          status code ASF (positions 60-62),
                                          or source code 1 or 3 (position
                                          200) and record status code
                                          (positions 60-62) not a cross-
                                          referenced stay (CRM, CRX)
     
  51-52                                    Reported Year of Admission or Beginning
                                           Year of Range
     
                             7950 70-93 = Year of admission or beginning year
                                          of range (1970-1993)
                              385 98    = Don't know
                               17 99    = Not ascertained
                             2183 Blank = Type D (position 199), or record
                                          status code ASF (positions 60-62),
                                          or source code (position 200) 1 or
                                          3 and record status code (positions
                                          60-62) not a cross-referenced stay
                                          (CRM, CRX)
     
    53-54                                 Reported Year of Admission - Ending Year of
                                          Range
     
                              492 72-93 = Ending year of range (1972-1993)
                            10043 Blank = No range given for reported year of
                                          admission, or type D (position
                                          199), or record status code ASF
                                          (positions 60-62), or source code
                                          (position 200) 1 or 3 and record
                                          status code (positions 60-62) not
                                          a cross-referenced stay (CRM, CRX)
     
 (55-59)                                  ID Number of Cross-Referenced Facility
                                          Status Stay
     
                                          Note:  The ID number on the 1982-84, 1986
                                          or 1987 NHEFS Facility Tape (positions 29-
                                          33) is used to reference stays in a
                                          hospital or nursing home that began during
                                          the 1982-84, 1986 or 1987 NHEFS periods and
                                          which continue into the 1992 survey period. 
                                          This variable is coded only for records
                                          with a CRM or CRX in positions 60-62 on the
                                          1992 file.
     
     55                           Survey Period Identifier of Cross-
                                  Referenced Facility Stay
     
                             1 1     = NHEFS 1982-84
                             7 2     = NHEFS 1986
                          189  3     = NHEFS 1987
                            9  S     = NHEFS Supplemental HCFS file
                         10329 Blank = Stay not cross-referenced 
     
     56-57                   Facility Number of Cross-Referenced Stay
     
                              206 01-10 = Stay number
                            10329 Blank = Stay not cross-referenced
     
    58-59                   Stay Number Within Facility of Cross-
                             Referenced Stay
     
                              206 01-03 = Stay number
                            10329 Blank = Stay not cross-referenced
     
     
     (60-62)                      RECORD STATUS
     
                                Note:  The record status section of the
                                record (positions 60-62) contains
                                information on the outcome of the request
                                for a health care facility stay.
     
     60-62                        Record Status Code

                                Note:  See Appendix A for an explanation of
                                the record status codes.
     
                            10535 ANO - XRD = Record status code  
     
     (63-198)                     Reported Conditions and Codes
     
                                  During the process of completing the
                                  Hospital and Health Care Facility Chart
                                  (HHCF) respondents described the conditions
                                  that led to their overnight facility stays. 
                                  This information is included as a text
                                  field on the stay record.  Space is
                                  allotted for the recording of up to four
                                  reasons for the hospital or nursing home
                                  stay (see positions 67-96, 101-130, 135-164
                                  and 169-198).
     
                                  A numeric code was assigned to each text
                                  description to aid the researcher in the
                                  use of this information (see positions 63-
                                  66, 97-100, 131-134, 165-168).  These
                                  variables should be used in conjunction
                                  with information in the abstract section,
                                  i.e., ICD-9-CM diagnosis codes, present on
                                  records with a record status code of MAT,
                                  ASF or CRM.  Appendix B contains a complete
                                  description of these codes.
     
     (63-96)                             First Reported Condition
     
     63-66                        Condition Code
     
                             7905 01-37 = Condition Code (See Appendix B)
                             2630 Blank = Source Code equal to 2 or 3 or D
                                          stay record or Record Status Code
                                          ASF or source code equal to 1 and
                                          record status code not CRM.
     
     67-96                                    Condition Text
     
                             7905 Description of reason for facility stay
                             2630  Blank =   Source Code equal to 2 or 3 or D
                                             stay record or Record Status Code
                                             ASF or source code equal to 1 and
                                             record status code not CRM.
     
        (97-130)                            Second Reported Condition
     
     97-100                                   Condition Code
     
                               2839  01-37 = Condition Code (See Appendix B)
                               7696  Blank =   Source Code equal to 2 or 3 or D
                                               stay record or Record Status Code
                                               ASF or source code equal to 1 and
                                               record status code not CRM or only
                                               one condition reported
     
     
     101-130                                  Condition Text
     
                             2839 Description of reason for facility stay
                             7696  Blank =   Source Code equal to 2 or 3 or D
                                             stay record or Record Status Code
                                             ASF or source code equal to 1 and
                                             record status code not CRM or only
                                             one condition reported
     
     (131-164)                           Third Reported Condition
     
     131-134                      Condition Code
     
                                 562  01-37 = Condition Code (See Appendix B)
                                9973  Blank =   Source Code equal to 2 or 3 or D
                                                stay record or Record Status Code
                                                ASF or source code equal to 1 and
                                                record status code not CRM or less
                                                than three conditions reported
     
     135-164                                  Condition Text
     
                              562 Description of reason for facility stay
                              9973  Blank =   Source Code equal to 2 or 3 or D
                                              stay record or Record Status Code
                                              ASF or source code equal to 1 and
                                              record status code not CRM or less
                                              than three conditions reported
     
          (165-198)                           Fourth Reported Condition
     
     165-168                                  Condition Code
     
                                     122  01-37 = Condition Code (See Appendix B)
                                   10413  Blank =   Source Code equal to 2 or 3 or D
                                                    stay record or Record Status Code
                                                    ASF or source code equal to 1 and
                                                    record status code not CRM or less
                                                    than four conditions reported
     
     169-198                      Condition Text
     
                                    122  Description of reason for facility stay
                                    10413  Blank =   Source Code equal to 2 or 3 or D
                                                     stay record or Record Status Code
                                                     ASF or source code equal to 1 and
                                                     record status code not CRM or less
                                                     than four conditions reported
     
    199                            Type of Stay Flag
     
                               27 C    =   A reported stay with admission date
                                           up to one year prior to the date of
                                           last interview, i.e. the NHEFS
                                           1982-84, 1986 or 1987 if
                                           interviewed at any followup or date
                                           of NHANES I Examination if not
                                           interviewed since exam.
     
                              1  D     =   A reported stay with admission date
                                           more than one year prior to date of
                                           last interview and the facility had
                                           not been contacted previously.  If
                                           there were multiple reported stays
                                           in the same facility that were all
                                           type D (more than one year prior to
                                           last interview) these stays were
                                           consolidated into one entry in the
                                           tracking system.  If an in-scope
                                           abstract was received in response
                                           to a type D report, the abstract
                                           was never matched, but assigned a
                                           record status code of ASF
                                           (positions 60-62).  The type D
                                           report was then removed from the
                                           file.  The type D report remaining
                                           on the final file was not able to
                                           be resolved.
     
                          10507  Blank =   In-scope stay; a reported date of
                                           admission after the last interview
                                           date.  This field is also blank for
                                           record status codes of ASF, CRM or
                                           CRX (positions 60-62).
     
                                    Note: This variable identifies reported
                                          facility stays as in-scope or out-of-scope
                                          for the NHEFS 1992 interview period. 
                                          Reported dates of admission of don't know
                                          (989898) or not ascertained (999999) in
                                          positions 47-52 were considered in-scope.
    
    200                             Source of Report of Stay that Initiated
                                     Request for Abstract
     
                              170  1     = Information from death certificate
                               270 2     = Information from hospital abstract
                                           report
                               222 3     = Information from other source
                              7899 4     = Information from NHEFS 1992
                                           interview
                              1974 Blank = Not a requested stay.  Additional
                                           stay information obtained from
                                           facility (record status code ASF
                                           positions 60-62).  ASF may also be
                                           coded as source code 3.
     
     201-204                           10535  Blank
     
     (205-379)                             ABSTRACT DATA
     
                                           Note:  The abstract data portion of the
                                           record (positions 205-379) contains
                                           information obtained from an abstract form
                                           returned by the facility.  This section of
                                           the stay record (excluding positions 207-
                                           208) will be blank when a facility did not
                                           return an abstract form for a stay.
     
     205-206                      Abstract Number
     
                             7996 01-27 = Number of abstract
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
                               Note:  For each subject, a two digit number
                                      was assigned consecutively to each abstract
                                      form received.
     
     207-208                      Total Number of Abstracts Received
     
                            10535 00-27 = Total number of abstracts received
     
                               Note:  This number represents the total
                                      number of abstracts received for each
                                      subject.  The total number is repeated on
                                      each subject record.
     
     209                          Facility Record Type
     
                             7061 1     = Hospital
                              935 2     = Nursing home
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     (210-215)                                Date of Admission
     
     210-211                             Month of Admission
     
                             7996 01-12 = Month of admission
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     212-213                                  Day of Admission
     
                             7996 01-31 = Day of admission
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     214-215                                  Year of Admission
     
                             7996 73-93 = Year of admission (1973-1993)
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     (216-221)                    Date of Discharge
     
                                  Note:  When a subject had a brief break 
                                         in a nursing home stay not due to a
                                         hospitalization, the nursing home stays
                                         were combined into one long stay with the
                                         latest discharge date assigned to the stay. 
                                         The information contained in the report and
                                         abstract sections of the stay is from the
                                         earliest abstract.  For example:  subject A
                                         was in a nursing home from 10-31-91 to 12-
                                         22-91.  The subject was readmitted to the
                                         same nursing home 1-3-92 and stayed until
                                         his death 3-5-92.  No information is
                                         available for 12-22-91 to 1-3-92.  These 2
                                         stays would appear on the file as 1 stay
                                         from 10-31-91 to 3-5-92.  Length of stay
                                         would be calculated on the entire stay (see
                                         positions 222-225).  If the break in the
                                         nursing home was due to an interspersed
                                         hospitalization, the nursing homes stays
                                         were collapsed as described above and a
                                         code was entered in the related stay
                                         section (see positions 380-429).
     
     
     216-217                      Month of Discharge
     
                             7816 01-12 = Month of discharge
                              175 97    =     Inapplicable (still at facility on
                                              date of 1992 interview)
                               5  99    = Not ascertained
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     218-219                                  Day of Discharge
     
                             7816 01-31 = Day of discharge
                              175 97    =     Inapplicable (still at facility on
                                              date of 1992 interview)
                               5  99    = Not ascertained
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     220-221                      Year of Discharge
     
                             7816 73-93 = Year of discharge (1973-1993)
                              175 97    =     Inapplicable (still at facility on
                                              date of 1992 interview)
                               5  99    = Not ascertained
                             2539 Blank =     Stay reported, no abstract form
                                              received
     
     222-225                                  Length of Facility Stay
     
                               37 0000     =  Died on day of admission
                            7779 0001-5644 =  Total number of days in
                                                facility
                              175 9997     = Inapplicable (still at
                                             facility on date of 1992
                                             interview)
                               5 9999      =    Not ascertained
                            2539 Blank     =    Stay reported, no abstract
                                                  form received
     
                              Note:  Length of stay is calculated by
                                     subtracting the date of admission from the
                                     date of discharge.  For subjects with
                                     nursing home stays, brief breaks were
                                     collapsed into one continuous nursing home
                                     stay  (see positions 216-221).  For
                                     subjects with information coded in the
                                     related stays section (see positions 380-
                                     429) length of stay will include time spent
                                     in other facilities.
     
  226                              Was the Patient in Cardiac Intensive Care
                                   Unit?
     
                              699 1     = Yes
                             6024 2     = No
                              935 7     = Inapplicable (facility is a nursing
                                             home)
                              338 9     = Not ascertained
                             2539 Blank = Stay reported, no abstract form
                                            received
     
     227-229                                 Number of Days in Cardiac Intensive Care
                                             Unit
     
                          645 000-037    =   Number of days
                             7297 997    =   Inapplicable (position 226 =
                                                 2,7,9)
                               54 999    =   Not ascertained
                             2539 Blank  =   Stay reported, no abstract
                                             form received
     
                                   Note:  A length of stay of 0 days occurred
                                          when a subject was admitted to the facility
                                          and died on the day of admission.
     
  230                                     Was the Patient In Other Intensive Care
                                           Unit?
     
                              742 1     = Yes
                             5821 2     = No
                              935 7     = Inapplicable (facility is a nursing
                                            home)
                              498 9     = Not ascertained
                             2539 Blank = Stay reported, no abstract form
                                            received
     
     231-233                        Number of Days in Other Intensive Care Unit
     
                           642 000-081  = Number of days
                           7254 997     = Inapplicable (Position 230 =
                                            2,7,9)
                            100 999     =  Not ascertained
                           2539 Blank   =  Stay reported, no abstract
                                             form received
     
                                 Note:  A length of stay of 0 days occurred
                                        when a subject was admitted to the facility
                                        and died on the day of admission.
     
     234                                 Patient Admitted to Nursing Home From:
     
                              214 1     = Private residence
                              558 2     = Acute care hospital
                                8 3     = Chronic disease hospital
                              144 4     = Other nursing home
                             7061 7     = Inapplicable (facility is a
                                            hospital)
                               11 9     = Not ascertained
                             2539 Blank = Stay reported, no abstract form
                                             received
     
     235                                     Disposition of Hospital Patient
     
                             4900 1     =    Routine discharge/discharged home
                               18 2     =    Left against medical advice
                             1096 3     =    Discharged/transferred to another
                                             facility or organization
                              448 4     =    Discharged/referred to organized
                                             home care service
                              461 5     =    Died
                                8 6     =    Not discharged/still in hospital on
                                             the date of 1992 interview
                              935 7     =    Inapplicable (facility is a nursing
                                             home)
                              130 9     =    Subject discharged, disposition not
                                             ascertained
                             2539 Blank =    Stay reported, no abstract form
                                             received
     
     236                                     Disposition of Nursing Home Patient
     
                              167 1     =    Not discharged/still in a nursing
                                             home on date of 1992 interview
                               89 2     =    Discharged to private
                                             residence/referral to organized
                                             home care services
                              327 3     =    Died
                               86 4     =    Discharged to private residence/no
                                             referral
                              260 5     =    Transferred to another facility
                             7061 7     =    Inapplicable (facility is a
                                             hospital)
                                6 9     =    Subject discharged, disposition not
                                             ascertained
                             2539 Blank =    Stay reported, no abstract form
                                             received
     
  237                                     Transferred to Another Health Care Facility
     
                              139 1      =   Acute care hospital
                              108 2      =   Other nursing home
                                1 3      =   Chronic disease hospital
                               10 4      =   Other
                             7736 7      =   Inapplicable (Position 236 =
                                             1,2,3,4,7 or 9)
                                  2 9    =         Not ascertained
                             2539 Blank  =   Stay reported, no abstract
                                             form received
     
     238-239                                 Number of Diagnoses
     
                             7968 01-19  =   Number of diagnoses
                               28 99     =   Not ascertained
                             2539 Blank  =   Stay reported, no abstract
                                             form received
     
                                   Note:  This variable identifies the total
                                          number of diagnoses entered on the
                                          abstract.  The number of coded diagnoses
                                          may exceed the maximum number allowed on
                                          the data tape (10).
     
     240-245                      Principal Diagnosis
     
                                        7968 ICD-9-CM Code
                               28 999999 =   Not ascertained
                              2539 Blank =   Stay reported, no abstract
                                             form received
     
                                       Note:  See medical coding specifications.
     
     246-250                      Principal Diagnosis E Code
     
                                         571 ICD-9-CM Code
                             9964 Blank  =   Stay reported, no abstract
                                             form received or principal
                                             diagnosis does not require E
                                             code
     
                                     Note:  See medical coding specifications.
     
     251-256                      Second Diagnosis
     
                                        6950 ICD-9-CM Code
                             1046 999997     =    Inapplicable (only one
                                                  diagnosis coded)
                             2539 Blank      =    Stay reported, no abstract
                                                  form received
     
                                Note:    See medical coding specifications.
     
     257-261                             Second Diagnosis E Code
     
                              117 ICD-9-CM Code
                                 1046 99997  =   Inapplicable (only one
                                                  diagnosis coded)
                                 9372 Blank  =   Stay reported, no abstract
                                                 form received or second
                                                 diagnosis does not require E
                                                 code
     
                                 Note:  See medical coding specifications.
     
     262-267                             Third Diagnosis
     
                             5748 ICD-9-CM Code
                                 2248 999997 =   Inapplicable (less than three
                                                  diagnoses coded)
                                 2539 Blank  =   Stay reported, no abstract
                                                  form received
     
                                  Note:  See medical coding specifications.
     
     268-272                             Third Diagnosis E Code
     
                                         112 ICD-9-CM Code
                                  2248 99997  =   Inapplicable (less than three
                                                   diagnoses coded)
                                  8175 Blank  =   Stay reported, no abstract form received or third
                                                   diagnosis does not require E
                                                   code
     
                                Note:  See medical coding specifications.
     
          273-278                      Fourth Diagnosis
     
                                        4456 ICD-9-CM Code
                                 3540 999997 =   Inapplicable (less than four
                                                  diagnoses coded)
                                 2539 Blank  =   Stay reported, no abstract
                                                  form received
     
                                 Note:  See medical coding specifications.
     
     279-283                             Fourth Diagnosis E Code
     
                               92 ICD-9-CM Code
                                 3540 99997  =   Inapplicable (less than four
                                                  diagnoses coded)
                                 6903 Blank  =   Stay reported, no abstract
                                                 form received or fourth
                                                 diagnosis does not require
                                                 E code
     
                           Note:  See medical coding specifications.
     
     284-289                      Fifth Diagnosis
     
                                        3258 ICD-9-CM Code
                                 4738 999997 =  Inapplicable (less than five
                                                 diagnoses coded)
                                 2539 Blank  =  Stay reported, no abstract
                                                 form received
     
                           Note:  See medical coding specifications.
     
     290-294                      Fifth Diagnosis E Code
     
                                          51 ICD-9-CM Code
                                4738 99997  =  Inapplicable (less than five
                                                diagnoses coded)
                                5746 Blank  =  Stay reported, no abstract
                                                form received or fifth
                                                diagnosis does not require E
                                                code
     
                                Note:  See medical coding specifications.
     
     295-300                                 Sixth Diagnosis
     
                                        2201 ICD-9-CM Code
                              5795 999997 =  Inapplicable (less than six
                                              diagnoses coded)
                              2539 Blank  =  Stay reported, no abstract
                                              form received
     
                                Note:  See medical coding specifications.
     
    301-305                                 Sixth Diagnosis E Code
     
                               45 ICD-9-CM Code
                             5795 99997  =  Inapplicable (less than six
                                             diagnoses coded)
                             4695 Blank  =  Stay reported, no abstract
                                             form received or sixth
                                             diagnosis does not require E
                                             code
     
                                Note:  See medical coding specifications.
     
     306-311                             Seventh Diagnosis
     
                                        1449 ICD-9-CM Code
                             6547 999997 =  Inapplicable (less than seven
                                             diagnoses coded)
                             2539 Blank  =  Stay reported, no abstract
                                             form received
     
                                             Note:  See medical coding specifications.
     
     312-316                             Seventh Diagnosis E Code
     
                               18 ICD-9-CM Code
                             6547 99997  =  Inapplicable (less than seven
                                             diagnoses coded)
                             3970 Blank  =  Stay reported, no abstract
                                             form received or seventh
                                             diagnosis does not require E
                                             code
     
                                    Note:  See medical coding specifications.
     
     317-322                             Eighth Diagnosis
     
                                         924 ICD-9-CM Code
                             7072 999997 =  Inapplicable (less than eight
                                             diagnoses coded)
                             2539 Blank  =  Stay reported, no abstract
                                             form received
     
                                    Note:  See medical coding specifications.
     
     323-327                                 Eighth Diagnosis E Code
     
                               26 ICD-9-CM Code
                             7072 99997  =  Inapplicable (less than eight
                                             diagnoses coded)
                             3437 Blank  =  Stay reported, no abstract
                                             form received or eighth
                                             diagnosis does not require E
                                             code
     
                                     Note:  See medical coding specifications.
     
     328-333                                 Ninth Diagnosis
     
                                         573 ICD-9-CM Code
                             7423 999997 =  Inapplicable (less than nine
                                             diagnoses coded)
                             2539 Blank  =  Stay reported, no abstract
                                             form received
     
                                  Note:  See medical coding specifications.
     
     334-338                                 Ninth Diagnosis E Code
     
                               17 ICD-9-CM Code
                            7423 99997  =  Inapplicable (less than nine
                                            diagnoses coded)
                            3095 Blank  =  Stay reported, no abstract
                                            form received or ninth
                                            diagnosis does not require E
                                            code
     
                                    Note:  See medical coding specifications
     
     339-344                             Tenth Diagnosis
     
                                         344 ICD-9-CM Code
                           7652 999997 =  Inapplicable (less than ten
                                           diagnoses coded)
                           2539 Blank  =  Stay reported, no abstract
                                           form received
     
                                  Note:  See medical coding specifications.
     
     345-349                             Tenth Diagnosis E Code
     
                               10 ICD-9-CM Code
                             7652 99997  =  Inapplicable (less than ten
                                             diagnoses coded)
                             2873 Blank  =  Stay reported, no abstract
                                             form received or tenth
                                             diagnosis does not require E
                                             code
     
                                     Note:  See medical coding specifications.
     
     350-351                                 Number of Procedures
     
                               7061 00-08 = Number of procedures
                                935 97    = Inapplicable (facility is a nursing
                                             home)
                               2539 Blank = Stay reported, no abstract form
                                             received
     
                                    Note:  This variable identifies the total
                                           number of procedures coded on the facility
                                           abstract.  The number of reported
                                           procedures from a hospital may exceed the
                                           maximum number of five coded on this data
                                           tape.
     
     352-355                                 First Procedure
     
                             2746 ICD-9-CM Code
                               5250 9997   =  Inapplicable (facility is a
                                               nursing home or no procedures
                                               coded)
                               2539 Blank  =  Stay reported, no abstract
                                               form received
     
                                  Note:  See medical coding specifications.
     
     356-359                                 Second Procedure
     
                              975 ICD-9-CM Code
                              7021 9997   =  Inapplicable (facility is a
                                              nursing home or only one
                                              procedure coded)
                              2539 Blank  =  Stay reported, no abstract
                                              form received
     
                                       Note:  See medical coding specifications.
     
     360-363                      Third Procedure
     
                                         319 ICD-9-CM Code
                              7677 9997   =  Inapplicable (facility is a
                                              nursing home or less than
                                              three procedures coded)
                              2539 Blank  =  Stay reported, no abstract
                                              form received
     
                                     Note:  See medical coding specifications.
     
     364-367                      Fourth Procedure
     
                                         112 ICD-9-CM Code
                             7884 9997   =  Inapplicable (facility is a
                                             nursing home or less than four
                                             procedures coded)
                             2539 Blank  =  Stay reported, no abstract
                                             form received
     
                                  Note:  See medical coding specifications.
     
     368-371                             Fifth Procedure
     
                               45 ICD-9-CM Code
                             7951 9997   =  Inapplicable (facility is a
                                             nursing home or less than five
                                             procedures coded)
                             2539 Blank  =  Stay reported, no abstract
                                             form received
     
                                     Note:  See medical coding specifications.
     
          372                          Pathology Report
     
                              334 1      =   Required and present
                              315 2      =   Required and not present
                             6412 6      =   Not required
                              935 7      =   Inapplicable (facility is a
                                             nursing home)
                             2539 Blank  =   Stay reported, no abstract
                                             form received
     
     373-379                           10535 Blank
                             
     (380-429)                               RELATED STAY CODES
     
                                  Note:  Residents in nursing homes are often
                                         admitted to hospitals during the course of
                                         their stays in the nursing home.  The
                                         related stay section of the record cross-
                                         links nursing home stays with interspersed
                                         hospital stays.
     
                                         In the case of nursing home records, this
                                         set of variables identifies hospital stays
                                         that occurred during the nursing home stay. 
                                         Up to 10 related stays can be listed.
     
                                         In the case of hospital records, this set
                                         of variables identifies the nursing home
                                         stay within which the hospital stay
                                         occurred.  Only one related stay is
                                         identified for hospital records.
     
                                         The Related Stay is identified by its
                                         Health Care Facility Stay ID Number
                                         (positions 29-33) of the record for that
                                         stay.
     
     (380-429)                    ID Number(s) of Related Stay(s)
     
     (380-384)                           ID of First Related Stay
     
     380                          Survey Period Identifier
                                         605 4    =         NHEFS 1992
                             9930 Blank  =   No related stays
     
     381-382                      Facility Number
     
                              605 01-91  =   Hospital/nursing home number
                             9930 Blank  =   No related stays
     
     383-384                                 Stay Number Within Facility
     
                              605 01-12  =   Stay number
                             9930 Blank  =   No related stays
     
          (385-389)                    ID of Second Related Stay
     
     385                                 Survey Period Identifier
     
                               88 4      =   NHEFS 1992
                            10447 Blank  =   No second related stay
     
     386-387                      Facility Number
     
                               88 01-82  =   Hospital/nursing home number
                            10447 Blank  =   No second related stay
     
     388-389                                 Stay Number Within Facility
     
                               88 01-13  =   Stay number
                            10447 Blank  =   No second related stay
     
     (390-394)                    ID of Third Related Stay
     
     390                          Survey Period Identifier
     
                               38 4      =   NHEFS 1992
                            10497 Blank  =   No third related stay
     
     391-392                      Facility Number
     
                               38 01-71  =   Hospital/nursing home number
                            10497 Blank  =   No third related stay
     
     393-394                      Stay Number Within Facility
     
                               38 01-14  =   Stay number
                            10497 Blank  =   No third related stay
     
     (395-399)                               ID of Fourth Related Stay
     
     395                          Survey Period Identifier
     
                               15 4      =   NHEFS 1992
                            10520 Blank  =   No fourth related stay
     
     396-397                                 Facility Number
     
                               15 01-05  =   Hospital/nursing home number
                            10520 Blank  =   No fourth related stay
     
     398-399                                 Stay Number Within Facility
     
                               15 01-15  =   Stay number
                            10520 Blank  =   No fourth related stay
     
     (400-404)                               ID of Fifth Related Stay
     
     400                          Survey Period Identifier
     
                                9 4      =   NHEFS 1992
                            10526 Blank  =   No fifth related stay
     
     401-402                      Facility Number
     
                                9 02-05  =   Hospital/nursing home number
                            10526 Blank  =   No fifth related stay
     
     403-404                                 Stay Number Within Facility
     
                                9 02-10  =   Stay number
                            10526 Blank  =   No fifth related stay
     
     (405-409)                               ID of Sixth Related Stay
     
     405                          Survey Period Identifier
     
                                7 4      =   NHEFS 1992
                            10528 Blank  =   No sixth related stay
     
     406-407                      Facility Number
     
                                7 02-03  =   Hospital/nursing home number
                            10528 Blank  =   No sixth related stay
     
     408-409                      Stay Number Within Facility
     
                                7 01-09  =   Stay number
                            10528 Blank  =   No sixth related stay
     
     (410-414)                               ID of Seventh Related Stay
     
     410                          Survey Period Identifier
     
                                4 4      =   NHEFS 1992
                            10531 Blank  =   No seventh related stay
     
     411-412                      Facility Number
     
                                4 02-03  =   Hospital/nursing home number
                            10531 Blank  =   No seventh related stay
     
     413-414                                 Stay Number Within Facility
     
                                4 02-15  =   Stay number
                            10531 Blank  =   No seventh related stay
     
     (415-419)                               ID of Eighth Related Stay
     
     415                          Survey Period Identifier
     
                                  1 4    =   NHEFS 1992
                            10534 Blank  =   No eighth related stay
     
     416-417                                 Facility Number
     
                                  1 02   =   Hospital/nursing home number
                            10534 Blank  =   No eighth related stay
     
          418-419                      Stay Number Within Facility
     
                                  1 01   =   Stay number
                            10534 Blank  =   No eighth related stay
     
     (420-424)                    ID of Ninth Related Stay
     
     420                                 Survey Period Identifier
     
                            10535 Blank  =   No ninth related stay
     
     421-422                      Facility Number
     
                            10535 Blank  =   No ninth related stay
     
     423-424                                 Stay Number Within Facility
     
                            10535 Blank  =   No ninth related stay
     
     (425-429)                    ID of Tenth Related Stay
     
     425                          Survey Period Identifier
     
                            10535 Blank   =   No tenth related stay
     
     426-427                      Facility Number
     
                            10535 Blank   =   No tenth related stay
     
     428-429                      Stay Number Within Facility
     
                            10535 Blank   =   No tenth related stay
     
         
Figure 1
     
NHANES I Epidemiologic Followup Study (NHEFS)
  Health care facility record layout
     
     - Facility
       identifiers
     - Reported date 
       of admission
     - Reported
       cause of
       admission
     - Source of
       report
          
   
        Match
            or
        reason for
        non-match
     - Actual dates
       admission and
       discharge
     - ICD-9-CM 
       diagnoses
     - Discharge
       status from 
       hospitals and 
       nursing homes
     - Codes assign-
       ed by NCHS to
       identify
       stays con-
       tained within
       other stays
  
   
                         Record                                 Related
      Report Section     Status Section      Abstract Section   Stay Section
     
    
Figure 2
     
NHANES I Epidemiologic Followup Study (NHEFS)
Examples of matching process and record status codes
     
Record status code
     
       Match    
         Report Section
              Match
               Abstract Section
       Non-match
         Report Section
          Non-match code
         No Abstract
         received
    
      Additional abstract found
         No Report section
              ASF
         Abstract Section
  
    
APPENDIX A
 
RECORD STATUS CODES
 (positions 60-62)     
     Code  Frequency      Description
     
                          ANO -   216 "Authorization Not Obtained."  This code indicates
                          that the subject or proxy refused to sign the Medical
                          Authorization Form (MAF).  These stays are not
                          requested from the reported facilities.
     
                          ASF -  2182 "Additional Stay Found."  This code was assigned when
                          a returned in-scope abstract could not be matched to
                          a reported stay.  This code was also assigned to in-
                          scope abstracts that were received as a result of an
                          inquiry generated by a type D report (Position 199). 
                          The type D report was deleted from the final file.
     
                          CRM -   196 "Cross-Referenced Match."  This code indicates a stay
                          that was begun prior to the NHEFS 1992 survey period
                          and continues into the 1992 survey period.  For this
                          type of stay, the abstract is brought forward from
                          the previous wave.  The discharge date and discharge
                          status information are the only positions that are
                          updated.  The admission date is prior to the most
                          recent interview because this is a continuing stay. 
                          Thus, it appears to be, but is not, out-of-scope for
                          1992.
     
                          CRX -    10 "Cross-Referenced Non-Match."  A code assigned by
                          NCHS staff to close out a stay that was begun in a
                          previous wave and was reported to have continued into
                          the 1992 Survey period, yet no in-scope abstract was
                          received for the 1992 survey period.
     
                          FNC -   111 "Facility Never Contacted."  This code was assigned
                          when the facility was not contacted for the following
                          reasons:  the respondent could not recall the name of
                          the facility; the facility was closed; the facility
                          could not be located; and facility located outside
                          the United States.
     
                          MAT -  5618 "Record Match."  This code was assigned when a
                          received abstract matched a reported stay.  This code
                          was assigned to in-scope and type C (position 199)
                          reports, but never to type D reports.  In-scope
                          abstracts that were received as the result of a type
                          D report were assigned an ASF code. 
     
                          ONR -   261 "Other Non-Response."  This code was assigned to a
                          stay when no response for the stay request had been
                          received from the facility by the end of the study
                          period.
     
     Code  Frequency      Description
     
                          REF -   248 "Refused."  This code was assigned if a facility
                          refused to send back the abstract requested.  It is
                          record, not subject, specific.  For example, a
                          facility may have sent some abstracts for a subject
                          but refused to send other abstracts for the same
                          subject.
     
                          XNH -   317 "Subject Never at Facility."  This code was used when
                          the facility indicated that the patient was never
                          admitted to that facility.
     
                          XNS -  1299 "Other - No Stay Found."  This code was assigned when
                          a facility responded it was unable to send abstracts
                          because no in-scope stays were found at the facility,
                          or when the facility returned the request form
                          without abstracts and provided no explanation for the
                          failure to provide them.
     
                          XRD -    77 "Record Destroyed or No Longer Available."  This code
                          was assigned if the facility attempted to locate the
                          abstract but stated that it no longer existed, i.e.,
                          was destroyed, or lost.
     
APPENDIX B     
NUMERIC CODES FOR REPORTED CONDITIONS ON
HEALTH CARE FACILITY STAY RECORDS
 (positions 63-66, 97-100, 131-134, 165-168)
     
Code for reported   Condition

        Condition      Description
     
             01           Arthritis     
             02           Gout     
             03           Heart attack     
             04           Another heart condition besides heart attack     
             05           Coronary bypass surgery     
             06           Pacemaker repair, insertion and/or replacement     
             07           (Not assigned in 1987 or 1992 files, see notes below)     
             08           Stroke or CVA (cerebrovascular accident)     
             09           Diabetes     
             10           High blood pressure     
             11           Cancer and/or cancer treatment other than skin cancer     
             1101         Malignant melanoma     
             1102         Skin cancer other than malignant melanoma     
             12           Fractured hip     
             13           Another type of bone fracture besides a hip fracture     
             14           (Not assigned in 1987 or 1992 files, see notes below)     
             15           Surgery     
             16           Don't know     
             17           Not ascertained     
             18           Tests/observation/x-rays/physical exam     
             19           Digestive/endocrine condition     
             20           Respiratory condition (including influenza and 
                          pneumonia)     
             21           Infection        
             22           Kidney/bladder/urinary condition      
             23           Debility/pain     
             24           Male reproductive condition     
             25           Musculoskeletal problem or injury other than a
                          fracture     
             26           Circulatory condition     
             27           Female reproductive condition     
             28           Mental illness     
             29           Neurologic condition     
             30           Nutritional condition or dehydration     
             31           Bleeding or blood disorder     
             32           Skin condition     
             33           Condition not elsewhere coded     
             34           Admission to a facility other than an acute care
                          hospital     
             35           In a facility at time of death     
             36           Cataracts     
            3603         Eye problem other than cataracts, detached retina or
                         glaucoma     
             37           A fall
     
       
APPENDIX B (continued)     
Guidelines for Use of Numeric Codes for Reported Conditions     
     
Background     
     During the process of completing the Hospital and Health Care Facility
     (HHCF) chart respondents were asked to describe the conditions that led
     to their facility stays and this information is included as a text field
     on the stay record.  The text portion of the reported condition contains
     standard nomenclature for certain conditions (see Type A conditions below)
     or the respondent's own words.  If necessary the respondent's descriptions
     was edited to fit into the 30 positions available in the record.  A
     numeric code was also assigned to each description.  This was done so that
     users would not have to deal with alphabetic description fields when
     investigating reasons for facility stays.  Space is allotted on the report
     section of the facility stay record for recording of up to four reasons
     for the hospitalization or nursing home stay (positions 63-198 of the HCFS
     record).     
     Note that codes "07" and "14" are not included in the coding structure for
     the 1987 and 1992 files.  These codes had been assigned to conditions in
     the 1982-84 and 1986 followups.  The 1987 and 1992 followup questionnaires
     differ from the earlier versions and sufficient information was not
     collected to assign these codes.     
     Reported conditions and their associated codes can be divided into six
     types depending on where in the interview the stay was reported and the
     amount of information obtained:  specific conditions included in Section
     B of the interview (Type A); conditions which are well-defined but for
     which no question exists in Section B of the interview (Type B); unknown
     conditions (Type C); conditions about which there is no specific question
     in Section B but for which sufficient information is available to
     attribute them to disorders of a major body system (Type D); conditions
     that are broadly defined and/or cannot be attributed to a single major
     body system (Type E); and conditions that cannot be classified into any
     of the above categories (Type F).  Each condition type, the associated
     codes and the rules for assigning the reported conditions to the
     categories of the coding structure are described in detail below.
     
Type A - Conditions about which the respondent was asked in section B of
         the interview.  For example, if a respondent answered "yes" to 
         question B-17 ("Were you hospitalized for your arthritis?"), 
         then a condition code of "01" and a text field containing 
         "arthritis" would be included on the facility stay record.  

Type A conditions are:   
                                01  Arthritis (B-17)
                                02  Gout (B-17)
                                03  Heart attack (B-23)
                                04  Other heart conditions (B-24)
                                05  Coronary bypass surgery (B-27)
                                06  Procedures for pacemakers (B-29)
                                08  Stroke (B-35)
                                09  Diabetes (B-42)
                                10  High blood pressure (B-52)
                                11  Cancer (B-66) other than skin cancer
           
   1101                   Malignant Melanoma (B-60)
   1102                   Skin cancer (B-63) other than malignant melanoma
                                12  Fractured hip (B-80)
                                20  Pneumonia, bronchitis and influenza (B-90)
                                Note: this code is also found under Type D
                                      because other respiratory conditions are 
                                      also coded to category 20
                                22  Kidney, bladder or urinary problem (B-97)
                                34  Care in non-acute care facility (B-121)
                                35  In a facility at death (B-127) 
                                36  Cataracts (B-108)
                                37  A fall (B-89)
     
     Complete agreement between  responses to the questions in section B and
     Type A condition codes on the facility stay file should not be expected. 
     There are several reasons for a lack of agreement between these two data
     sources.     
     First, the respondent may report a facility stay for a given condition in
     the interview and yet no facility stay record containing the condition may
     appear on the HCFS file.  This would result if: (1) it was determined that
     the hospitalization did not last overnight causing the stay to be deleted
     from the HCFS file; or (2) the reported stay was found to be "out-of-
     scope".  (See the introduction to this codebook and the Plan and Operation
     for definitions of out-of-scope stays.)       
     Second, data may be inconsistent between the interview and the HCFS file
     if the respondent remembered and reported a condition after responding to
     the corresponding question in Section B of the interview.  This tended to
     occur at the time the interviewer was recording information on the HHCF
     chart.  For example, while recording information on a stay for high blood
     pressure, the respondent may add that he/she was also hospitalized at that
     time for a heart condition.  The respondent may not have reported the
     hospitalization when asked about heart conditions in question B-24 and the
     Section B information may not have been updated to reflect this additional
     condition.  However, heart condition would appear on the HCFS file.          
Type B - Conditions which do not have a corresponding question in Section
         B of the interview but for which sufficient descriptive information 
         is available to allow them to be easily coded:
     
                         13  Bone fracture
                         18  Tests and observation     
Type C - Unknown conditions:
     
                         16  Don't know
                         17  Not ascertained  
                   
Type D - Conditions for which there is not a specific question in Section
         B of the interview but which can be attributed to disorders of a 
         major body system:
     
                        19  The digestive/endocrine system
                        20  The respiratory system
                        Note: this code is also found under Type A
                              because the specific question about pneumonia,
                              bronchitis and influenza (B-90) is coded to the
                              general category
                        24  The male reproductive system
                        25  The musculoskeletal system
                        26  The circulatory system (except strokes)
                        27  The female reproductive system
                        29  Neurologic disorders
                        31  Blood disorder/bleeding
                        32  Skin problem

      3603  Eye problem (except cataracts, detached retina or glaucoma)
     
Type E - Conditions which are broadly defined or are attributed to
         problems of more than one major body system:
     
                        15  Surgery
                        21  Infections
                        23  Debility and pain
                        28  Mental illness
                        30  Nutrition and dehydration
     
Type F - All conditions that cannot be assigned to one of the above codes:
     
                        33  Other conditions
     
     Additional information on reasons for a facility stay is available in the
     abstract section of the record (positions 205-379) if an abstract has been
     matched to the report.  In general information from the abstract is
     considered a more accurate determination of the conditions associated with
     the stay than are the reported conditions.  The condition codes in the
     report section of stay records do provide useful information in the
     absence of a medical abstract.  Both flexibility and caution should be
     exercised when selecting stays based on these codes.  In order to help the
     analyst use these condition codes effectively, a description of the code
     assignment procedure along with an example is provided.
     
Rules for Assignment     
     The numeric codes were assigned to the respondent's non-technical
     descriptions by trained medical coders.  In order to minimize variation
     among the coders assigning these codes, precedence rules were defined. 
     Generally, a condition was coded to the most specific category in which
     it could be placed.  The assignment rules are described below in priority
     order, e.g. Rule 2 was used only if Rule 1 did not apply and so forth.  
     
             Rule 1: If a condition was one about which there was a
             specific question in Section B of the interview, the
             code appropriate for that question was assigned. 
             (Type A conditions)     
             Rule 2: If the textual description could be coded to a
             narrowly defined condition not referenced in Section
             B or to the unknown category, the appropriate Type B
             or Type C code was assigned.     
             Rule 3: Conditions that could not be coded to a specific
             question but could be coded to a major body system
             were assigned the appropriate Type D code.     
             Rule 4: General descriptions, symptoms and conditions not
             coded by rules 1 through 3 were coded at the
             discretion of the medical coder, again with emphasis
             on as much specificity as possible.  For example,
             "HEADACHES, BRAIN TUMOR" would be coded to "29 -
             Neurologic disorders", not to "23 - Debility and
             pain".  (Type D or Type E conditions)       
             Rule 5: Everything that could not be assigned a code after
             applying the above rules was coded to "33 - Other
             conditions".  (Type F conditions)
     
Considerations for the data user     
     These precedence rules were used for all four followups.  However, since
     the questionnaires used in each followup differed slightly, the assignment
     of codes also differed.  Questions about specific conditions were not
     always included in all four questionnaires.  For example, Question B-63
     in the 1986 interview asked about overnight stays for surgery making
     condition code "15 -Surgery" a Type A condition in the 1986 followup. 
     There is no similar question in the 1982-84, 1987 or 1992 interviews,
     therefore, surgery is a Type E condition in the 1982-84, 1987 and 1992
     files.  In other cases, groups of conditions are combined into one
     question on one questionnaire but asked separately on another.  
     For example, T.I.A.'s and other strokes are combined in one question 
     in 1987 and 1992.  Since it was not possible to separate reports of 
     T.I.A.'s from other strokes in the 1987 and 1992 files, there are no 
     conditions assigned to codes "07" in these files.  There are reports 
     assigned to "07" in the 1982-84 and 1986 files since separate T.I.A. 
     and stroke questions were asked.  An attempt was made to include as 
     much detail in the code as possible.  The questionnaire in the 1982-84 
     followup included enough detail to separate specific digestive 
     conditions, such as colitis and gallbladder problems, from the general 
     category of digestive disorders. Therefore, the 1982-84 HCFS data file, 
     includes sub-codes under "19 - Digestive/endocrine system".  Thus, 
     analysts interested in colitis can identify cases from the reported 
     condition section of the 1982-84 file but not from the 1986, 1987 or 
     1992 files.  However, all files can be used to identify cases of the 
     digestive/endocrine system in general.  The analyst should refer to the 
     questionnaire and the condition coding structure in the HCFS data tape 
     codebook for the period of interest in order to obtain the maximal 
     amount of information available.     
     In using the condition codes to select records of interest, two
     characteristics of the coding structure should be considered: (1) the
     condition of interest may be found under more than one numeric code and
     (2) each numeric code covers more than one condition.        
     To illustrate the first situation, consider a search for all reported
     stays with breast biopsies.   A respondent might report a breast biopsy
     in response to the question relating to cancer and cancer treatment.  In
     this case the textual field would contain a description such as "BIOPSY
     OF RIGHT BREAST" and the numeric code assigned would be 11 (indicating a
     response to the cancer stay question).  Breast biopsies could also be
     reported in response to the surgery question in the 1986 followup and be
     assigned the code of 15.  If the biopsy was reported in response to
     question B-112 on the 1992 questionnaire, "Have you stayed in a hospital
     for any other reason...?", it would be assigned to code 18 - Tests and
     observation".  To identify breast biopsy cases it would be necessary to
     search the alphabetic fields for codes 11, 15 and 18.  In addition, the
     reports of breast biopsies include several wording variations, for
     example, "BREAST BIOPSY", "BIOPSY OF BREAST".  The analysts needs to
     investigate all possible wordings.      
     To illustrate the second situation, consider code 18 - "Tests and
     observation".   Over 250 different verbal descriptions have been coded to
     this category including a variety of radiological procedures, surgeries
     and physical examinations.  Selecting just on code 18 will result in a
     wide variety of procedures.  Those of a specific interest need to be
     identified by the textual description.       
     Analysts who wish to use these reports, should print and review all the
     reported condition codes and alphabetic descriptions from the Health Care
     Facility Stay data files.  Such a review will aid in (1) finding all the
     numeric condition codes under which the condition of interest will be
     found and (2) insuring that, within any numeric condition code, only the
     reports of interest will be selected.
     
     Finally, the condition codes in the report section should be used in
     conjunction with the information in the abstract section if it is
     available.  Returned abstracts were matched to reports if one of the
     reported conditions matched one of the discharge diagnoses on the
     abstract.  Other conditions reported for the same stay may or may not be
     confirmed in the matched medical abstract. If the condition of interest
     is not indicated as a discharge diagnosis on the medical record, the
     analyst may not want to accept the reported condition as a reason for the
     stay.  Similarly, conditions may be listed as discharge diagnoses that do
     not appear on the report section.  See the introduction to this codebook
     for a description of the match criteria.  

     



This page last reviewed: Thursday, January 28, 2016
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