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Scientific Data Documentation
National Survey of Ambulatory Surgery, 1995

1995 National Survey of Ambulatory Surgery (NSAS)
Public Use Data Tape Documentation


Abstract

This material provides documentation for users of the 1995 NSAS Public Use Data Tape. The NSAS was implemented by the National Center for Health Statistics (NCHS) in 1994. It covers ambulatory surgery procedures performed in hospitals and free-standing ambulatory surgery centers in the United States.

Section I describes the survey and includes information on the history and scope of the NSAS; the survey methodology, data collection and medical coding procedures; population estimates, measurement errors, and sampling errors.

Section II provides technical details of the tape.

Section III provides a detailed description of the contents of each data record.

Appendix A defines certain terms used in this document;
Appendix B contains the ICD-9-CM Addenda;
Appendix C provides population estimates to allow the user to calculate rates; and
Appendix D provides unweighted and weighted frequencies for selected descriptive variables.


I. Description of the National Survey of Ambulatory Surgery

Introduction--This document describes the 1995 National Survey of Ambulatory Surgery (NSAS) and provides information for users of the 1995 NSAS public use data file. This survey, conducted by the National Center for Health Statistics (NCHS) and implemented in 1994, covers ambulatory surgery procedures performed in hospitals and in free-standing ambulatory surgery centers in the United States. A brief description of the survey design and data collection procedures is given below. A more detailed description of the survey design, data collection procedures, and the estimation process has been published (1).

History--The National Survey of Ambulatory Surgery was undertaken to obtain information about the use of ambulatory surgery. Ambulatory, or outpatient, surgery has increased in the United States since the early 1980's. Two major reasons for this increase were advances in medical technology and cost containment initiatives.

On the medical side, many surgeries performed for hospital inpatients have moved to outpatient settings, in part because improvements in anesthesia and better analgesics for relief of pain have made surgery less complex and risky (2). Also, minimally invasive and non-invasive procedures, such as laser surgery, laparoscopy, and endoscopy, have been developed and are being performed with increasing frequency.

On the cost side, concern about rising health care costs led to changes in the Medicare program that encouraged the use of ambulatory surgery (3). In 1982 the Medicare program was expanded to cover care in ambulatory surgery centers. In 1983, a prospective payment system based on diagnosis-related groups (DRG=s) was adopted for hospital inpatient care. This system created strong financial incentives for hospitals to perform less complex surgery in an ambulatory setting. In the mid-1980's, the peer review organizations for Medicare established outpatient settings as the norm for certain surgeries and denied Medicare payment for hospital admissions deemed inappropriate or medically unnecessary. Many State Medicaid plans and private insurers followed the lead of the Medicare program and adopted similar policies.

As these changes went into effect, freestanding ambulatory surgery centers increased in number, from 239 centers that performed 380,000 procedures in 1983, to over 1,800 centers performing more than 3.2 million procedures ten years later (4). The number of ambulatory surgery procedures done in hospitals and freestanding settings combined rose from 5.4 million in 1983 to 16.2 million in 1993 (5).

The National Hospital Discharge Survey (NHDS), which has been conducted by the National Center for Health Statistics every year since 1965, includes information on procedures performed on inpatients (6). The NHDS remains a good source of data for surgical procedures, such as open-heart surgery or cesarean sections, that must be done on an inpatient basis. But for surgeries that can be performed on an ambulatory basis, NHDS estimates are incomplete. Thus the National Survey of Ambulatory Surgery was undertaken to provide data on the increasing use of this type of health care.


SURVEY METHODOLOGY

Source of the Data--The NSAS covers ambulatory surgery procedures performed in hospitals and free-standing ambulatory surgery centers (FSASC). The hospital universe includes noninstitutional hospitals exclusive of Federal, military, and Department of Veterans Affairs hospitals, located in the 50 States and the District of Columbia. Only short-stay hospitals (hospitals with an average length of stay for all patients of less than 30 days) or those whose specialty is general (medical or surgical) or children=s general are included in the survey. These hospitals must also have six beds or more staffed for patient use. The universe definition is the same as that used for the National Hospital Discharge Survey. The sampling frame for the hospital universe consisted of eligible hospitals listed in the 1993 SMG Hospital Market Database (7).

The universe of freestanding facilities includes FSASCs that are regulated by the States or certified by HCFA, the Health Care Financing Administration, for Medicare participation. The sampling frame consisted of facilities listed in the 1993 Freestanding Outpatient Surgery Center Database (8) and Medicare-certified facilities included in the HCFA Provider-of-Services (POS) file (9). Facilities specializing in dentistry, podiatry, abortion, family planning, or birthing are excluded. However, these procedures are not excluded from in-scope locations.

Sample design and data collection--The NSAS samples facilities using a multi-stage probability design with some facilities selected with certainty and others sampled with varying selection probabilities. Independent samples of hospitals and free-standing ambulatory surgery centers were drawn. The sample includes with certainty facilities which perform a high volume of ambulatory surgeries annually. Non-certainty facilities are selected using a stratified, cluster design, where the clusters are 198 primary sampling units (PSUs) that comprise the sample of PSUs used in the 1985-1995 National Health Interview Survey (NHIS). PSUs are counties or groups of counties, or county equivalents, or towns and townships (the latter in New England and Hawaii).

Noncertainty facilities were stratified by facility type (hospital versus freestanding), ambulatory surgery status of hospitals (i.e. whether or not the hospital performed such surgery), facility specialty, and geographic region. From each stratum containing fewer than six facilities, up to three facilities were selected by means of systematic random sampling, with selection probabilities proportional to size, where size is the number of ambulatory surgeries performed annually. For strata containing six or more facilities, first stage sampling involved selection of 112 PSUs, which are a probability subsample of the 198 PSUs in the 1985-94 NHIS sample. Some of these PSUs were sampled with certainty. Selection of noncertainty PSUs was performed within PSU strata defined within the four geographic regions by the number of people in the 1980 Census of Population and NHIS stratification variables. From each PSU stratum, the PSUs were selected with probability proportional to the projected 1985 population. The hospital sample is clustered within a probability subsample of 112 of those PSUs.

The second stage of the cluster design consisted of selection of noncertainty facilities from the sampled PSUs, using systematic random sampling with probabilities proportional to the annual number of ambulatory surgeries performed. For both hospitals and FSASCs, up to three facilities of each type and specialty were selected from each non-certainty PSU and up to 15 facilities were selected across the combined certainty PSUs in each region. For the stratum of hospitals which, according to the sampling frame data, did not have ambulatory surgery, a national sample of 50 hospitals was selected to permit estimates of surgery in hospitals that either change their status or differ from frame data. Any sampled facility which performed less than 50 ambulatory surgeries in the year prior to the data collection year was considered out-of-scope for the data collection year.

Within sampled facilities, a sample of ambulatory surgery visits was selected using a systematic random sampling procedure. Selection of visits within each facility was performed separately for each location where ambulatory surgery is performed. These locations include: main operating rooms, dedicated ambulatory surgery units, cardiac catherization laboratories, laser procedure rooms, endoscopy and laparoscopy rooms, etc. Locations within facilities that specialize in or are dedicated to inpatients, dentistry, abortion, podiatry, pain block, or small procedures are excluded. However, as mentioned above, these procedures are not excluded from in-scope locations.

Following selection of ambulatory surgery visits, data was abstracted from the medical record for each visit. The Medical Abstract Form used in data collection is shown in Figure 1. It contains items relating to the personal characteristics of the patient, including birth date or age, sex, race, zipcode, but not name and address; administrative information, including the date of the surgery, dispostion of the patient, and medical record number; principal and other additional expected sources of payment; and medical information, including diagnoses and surgical and nonsurgical procedures performed, as well as types of anesthesia administered and by whom. The medical record number, date of birth, and patient zip code, are confidential information and are not available to the public.

Response Rate--The 1995 NSAS sample included 333 FSASCs from the 1,732 facilities in the 1993 FSASC sampling frame; and 418 hospitals from the 6,267 listed in the 1993 hospital sampling frame. Of the 751 sampled facilities, 141 were found to be out-of-scope for the NSAS. One hundred twenty-one of the 610 in-scope facilities were nonresponding in 1995. The number of hospitals responding in 1995 was 294, which was 89 percent of the in-scope hospitals. The number of FSASCs responding in 1995 was 195, which represented 70 percent of the in-scope FSASCs.

Medical Coding and Edit--The medical information abstracted from the sampled medical records was coded centrally by NCHS contract staff. A maximum of seven diagnostic codes and six procedure codes was assigned for each sampled abstract. The system currently used for coding the diagnoses and procedures on the medical abstract forms is the International Classification of Diseases, 9th Revision, Clinical Modification, or ICD-9-CM (10).

Following conversion of the data on the medical abstract to computer tape, a final medical edit was accomplished by computer inspection and by a manual review of rejected records. Priority was given to medical information in the editing decision.

Users of the NSAS diagnostic and/or procedure data must take into account annual ICD-9-CM addenda. The addenda lists new codes, new fourth or fifth digits to existing codes, as well as other modifications. Changes go into effect October 1 of the calendar year. However, in order to preserve consistent coding throughout the data year, the NSAS coding for 1995 data is consistent with the ICD-9-CM and the Addenda through October 1, 1994. Appendix B lists the changes for 1986 through 1994.

Population Estimates--Appendix C shows population estimates provided by the U.S. Bureau of the Census. The estimates are of the U.S. civilian resident population on July l of the data year. These population estimates are consistent with those published in Current Population Reports, Series P-25; however, they are not official population estimates of the Bureau of the Census.

Measurement Errors and Limitations of the Data--As in any survey, results are subject to nonsampling or measurement errors, which include errors due to facility nonresponse, missing abstracts, information incompletely or inaccurately recorded on abstract forms, and processing errors.

In a very small number of records, the age or sex of the patient was missing. For these records, a legitimate value was imputed in such a way as to preserve the original, known distribution of the variable. Fewer than one percent of the records have an imputed age or sex value.

Forty-two percent of the records were missing a value for race of the patient. No attempt was made to impute for these missing values.

Figure 1. Medical abstract for the 1995 National Survey of Ambulatory Surgery


The determination of whether an ambulatory surgery facility is a hospital or a freestanding center is based on the SMG universe from which the facility is selected. In most cases it is apparent whether a facility is a hospital or a freestanding ambulatory surgery center, but some facilities are not easily classified. For example, a Afreestanding@ facility may be owned by a hospital but located some distance away. If such a facility is separately listed in the 1993 SMG Freestanding Outpatient Surgery Center Database and is selected into the NSAS sample from this universe, it is considered a freestanding facility.

The distinction between ambulatory and inpatient surgery is not always clear. According to the 1995 NSAS, an estimated 1.6 percent of ambulatory surgery visits were for patients subsequently admitted to the hospital as inpatients. Some of these patients had procedures which are currently performed exclusively on inpatients, such as coronary artery bypass graft, in addition to diagnostic procedures such as cardiac catheterization. These visits and their suspected Ainpatient@ procedures have not been eliminated from the data file because they are operationally part of the survey design. It is left to the prerogative of the researcher whether or not to include these procedures in an analysis. In NCHS publications for the 1994 NSAS, patients discharged to inpatient status were included in estimates of visits and procedures. For the 1995 NSAS, these visits were excluded from all tabulations.

Sampling errors--Statistics from the NSAS are derived by a multistage estimation procedure that produces essentially unbiased estimates. The estimation procedure has three basic components: (a) inflation by reciprocals of the probabilities of sample selection, (b) adjustment for nonresponse, and (c) population weighting ratio adjustments.

The standard error of a statistic is primarily a measure of sampling variability that occurs by chance because only a sample rather than the entire universe is surveyed. The relative standard error of the estimate is obtained by dividing the standard error by the estimate itself. The resulting value is multiplied by 100, so the relative standard error (RSE) is expressed as a percent of the estimate. Estimates of sampling variability were calculated with SUDAAN software, which computes standard errors by using a first-order Taylor series approximation of the deviation of estimates from their expected values. A description of the software and the approach it uses has been published (11).


Relative Standard Errors for Aggregate Estimates

Table 1 presents parameter estimates to be used in formulae for deriving the approximate relative standard errors for aggregate estimates. To provide error estimates that would be applicable to a wide variety of statistics, numerous variances were calculated and the best fit formula was derived. The formula is based on an empirically determined relationship between the size of an estimate X and its relative variance. The relative standard error is then derived by taking the square root of the relative variance. The relative standard error of an estimate X [RSE(X)], expressed as a percent, may be calculated from the formula:

                                               with a and b provided in Table 1.

For example, in 1995 the estimated number of ambulatory surgery visits to hospitals and free-standing ambulatory surgery centers by persons aged 65 and over with a first-listed diagnosis of cataracts (ICD-9-CM code 366) was 1,893,000 (excluding those vists admitted to hospitals as inpatients). Using the applicable constants from Table 1 for estimates by age produces:
                                             RSE(1,893,000) = 7.08 %

The relative standard error for the estimate of interest is 7.08 percent. From this the standard error is obtained by multiplying the relative standard error by the estimate:

                                             SE(1,893,000) = 1,893,000 * 7.08 % = 134,036

The standard error can be employed to generate confidence intervals for statistical testing. In this example, the 95% confidence interval for the estimate of the total number visits by persons aged 65 and over with a first-listed diagnosis of cataracts is:

                                            (1,893,000 - 2*134,036)<-> (1,893,000 + 2*134,036)

                                              1,624,928<-> 2,161,072


Relative Standard Error for Estimates of Percents

Approximate relative standard errors for estimates of percents may be calculated from Table 1 also. The relative standard error for a percent, 100 p (0<p<1), (expressed as a percent), may be calculated using the formula:

where 100p is the percent of interest, X is the base of the percent, and b is the parameter value, b, given in Table 1.

For example, in 1995 the estimated number of ambulatory surgery visits by persons 65 years old and over was 6,505,000 (excluding those admitted to hospitals as inpatients). This is 33.1 percent of the estimated 19,638,000 visits for that year. Using the applicable constants from Table 1 for estimates by age produces:

                                          RSE (.331) = 0.675%

The relative standard error for the estimate of interest is 0.675 percent. From this the standard error is obtained by multiplying the relative standard error by the estimate:

                                         SE(.331) = .331 * 0.675 % = .0022

The standard error can be employed to generate confidence intervals for statistical testing. In this example, the 95% confidence interval for the estimate of the percentage of ambulatory surgery visits by persons in the 65 and over age group is:

                                         (.331 - 2*.0022) <-> (.331 + 2*.0022)

                                           .327 <-> .335

                                          or, equivalently, 32.7% <-> 33.5 %


Table 1. Estimated parameters for relative standard error formulae for National Survey of Ambulatory Surgery aggregate
             statistics by statistic type: United States, 1995

Characteristic

First-listed Diagnoses

All-Listed Procedures

First-Listed Diagnoses - Hospitals

All-Listed Procedures - Hospital

First-Listed Diagnoses - Freestanding

All-Listed Procedures - Freestanding

a

b

a

b

a

b

a

b

a

b

a

b

Total

0.00909

562.626

0.00311

631.907

0.01056

570.914

0.00361

657.110

0.03554

165.845

0.01744

185.751

Sex

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Male

0.01047

443.044

0.00316

550.551

0.00341

604.130

0.00358

582.511

0.01671

151.962

0.01716

157.168

Female

0.00363

478.144

0.00315

595.095

0.00423

491.716

0.00372

626.102

0.01573

171.346

0.01429

228.421

Age

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Under 15 Years

0.00398

292.951

0.00454

324.459

0.00460

297.613

0.00528

338.096

0.02338

90.520

0.01844

168.458

15-44 years

0.00428

367.261

0.00365

518.410

0.00398

515.875

0.00413

566.628

0.01405

165.953

0.01834

163.806

45-64 years

0.00411

491.458

0.00410

490.427

0.00493

537.452

0.00522

507.419

0.01516

139.891

0.01376

190.778

65 years and over

0.00478

442.089

0.00373

468.539

0.00524

500.755

0.00433

506.908

0.02276

133.543

0.01768

175.078

Region

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Northeast

0.01262

583.116

0.01175

632.514

0.01416

650.219

0.01570

616.306

0.06337

24.874

0.07134

2.527

Midwest

0.00698

354.739

0.01162

936.993

0.00627

417.906

0.00654

398.770

0.07304

90.986

0.08396

453.098

South

0.01249

382.143

0.01064

388.178

0.01517

341.520

0.01206

412.919

0.02800

180.589

0.03209

155.536

West

0.01356

430.118

0.01417

479.870

0.01585

432.043

0.01866

379.185

0.09046

123.606

0.11146

96.489

Source of Payment

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Other Gov,WC

0.01196

247.518

0.01424

254.337

0.01411

277.945

0.01552

306.607

0.02550

97.809

0.03027

136.528

Medicare

0.00575

415.696

0.00469

433.157

0.00652

454.425

0.00589

444.574

0.02592

127.408

0.01800

168.580

Medicaid

0.00798

264.919

0.00968

263.673

0.00760

359.199

0.01099

269.647

0.02084

131.524

0.02300

143.428

Private Insurance

0.00383

517.014

0.00411

544.178

0.00432

548.910

0.00484

586.992

0.01637

177.139

0.01911

178.572

Other,SP,NC,NS

0.02278

361.270

0.02710

340.345

0.03456

423.555

0.04096

368.204

0.03375

98.962

0.04499

21.619


Presentation of Estimates
--Publication of estimates for the NSAS is based on the relative standard error of the estimate and the number of sample records on which the estimate is based (referred to as the sample size). Estimates are not presented in NCHS reports unless a reasonable assumption regarding the probability distribution of the sampling error is possible.

Based on consideration of the complex sample design of the NSAS, the following guidelines are used for presenting the NSAS estimates:

If the sample size is less than 30, the value of the estimate is not reported.

If the sample size is 30-59, the value of the estimate is reported but should not be assumed reliable.

If the sample size is 60 or more and the relative standard error is less than 30 percent, the estimate is reported.

If the sample size is 60 or more but the relative standard error is over 30 percent, the estimate is reported but should not be assumed reliable.

How to Use the Data Tape--The NSAS records are weighted to allow inflation to national or regional estimates. The weight applied to each record is found in tape location 21-25. To produce an estimate of the number of visits, the weights for the desired records must be summed.

Appendix D contains unweighted and weighted frequencies for selected descriptive variables on the data tape. These may be used as a cross-check when processing the data on the user's system.

Questions--Questions concerning data on the tape should be directed to Maria Owings, Ph.D., Hospital Care Statistics Branch, Division of Health Care Statistics, National Center for Health Statistics, Presidential Building, Room 956, 6525 Belcrest Road, Hyattsville, Maryland 20782, (301)-436-7125.


REFERENCES

1. McLemore T and Lawrence L. Plan and Operation of the National Survey of   Ambulatory Surgery. Vital and Health
    Statistics, Series 1, No. 37. Hyattsville, MD: National Center for Health Statistics. 1997.

2. New surgical technologies reshape hospital strategies. Hospitals 66(9):30-36, 38, 40-42. 1992.

3. Leader S and Moon M. Medicare trends in ambulatory surgery. Health Affairs Spring: 158-170. 1989.

4. Durant G. Ambulatory surgery centers: surviving, thriving into the 1990's. Medical Group Management Journal 36(2): 16-18,
    20. 1989.

5. SMG Marketing Group, Inc. Outpatient surgery centers exceed 3 million cases. SMG Market Letter 8(5). 1995.

6. Graves EJ and Gillum BS. 1995 summary: National Hospital Discharge Survey. Advance data from Vital and Health
    Statistics; no 278. Hyattsville, Maryland: National Center for Health Statistics. 1996.

7. SMG Marketing Group, Inc. Hospital Market Database. Chicago: Healthcare Information Specialists. April 1993.

8. SMG Marketing Group, Inc. Freestanding Outpatient Surgery Centers Database. Chicago: Healthcare Information
    Specialists. 1993.

9. Health Care Financing Administration. Provider of Services Public Use File. Baltimore: 1993.

10. Public Health Service and Health Care Financing Administration. International Classification of Diseases, 9th Revision,
      Clinical Modification. Washington: Public Health Service. 4th ed. 1991.

11. Shah BV, Barnwell BG, Bieler GS. SUDAAN User=s Manual: Software for Analysis of Correlated Data, Release 6.40.
      Research Triangle Park, NC: Research Triangle Institute. 1995.


II. TECHNICAL DESCRIPTION OF TAPE

Data Set Name------------------------------------------------------BG00.NSAS95.PU
Number of REELS or CARTRIDGES--------------------------------------------------1
Number of Recording Tracks, REEL----------------------------------------------------9
Number of Recording Tracks, CARTRIDGE------------------------------------------18
Density for REEL (bpi)-------------------------------------------------------------6,250
Density for CARTRIDGE (bpi)---------------------------------------------------38,000
Language-----------------------------------------------------------------------EBCDIC
Parity--------------------------------------------------------------------------------Odd
Record Length-------------------------------------------------------------------------97
Block Size-------------------------------------------------------------------------32,689
Number of Records--------------------------------------------------------------121,564


III. RECORD FORMAT:

Location and Coding of Data Elements 

This section provides detailed information for each sampled record on the tape, with a description of each item included in the record. Data elements are arranged sequentially according to their physical location on the tape record. Data are derived from the abstract form; the SMG Hospital Market Tape is an alternative source of data; some items are computer generated.

Item Number

Tape

Location

Number of Positions

Item Description and Codes

1

1-2

2

Survey Year: 95

2

3

1

Facility Type:
1=Hospital
2=Free-Standing Ambulatory Surgery Center

3

4

1

Units for Age:
1 = Years
2 = Months
3 = Days

4

5-6

2

Age in years, months, or days:
If Units = Years: 0-99*
If Units = Months: 01-11
If Units = Days: 00-31

5

7

1

Age Flag:
1 = Value for Age was Imputed
2 = Value for Age was Not Imputed

6

8

1

Sex:
1 = Male
2 = Female

7

9

1

Sex Flag:
1 = Value for Sex was Imputed
2 = Value for Sex was Not Imputed

8

10

1

Race:
1 = White
2 = Black
3 = American Indian/Eskimo
4 = Asian/Pacific Islander
5 = Other
9 = Race Not Stated

9

11

1

Discharge Status:
1 = Routine discharge to customary residence
2 = Discharge to observation status
3 = Discharge to recovery care center
4 = Admitted to hospital as inpatient
5 = Surgery cancelled or terminated
6 = Other, specified
9 = Discharge Status Not Stated

10

12-13

2

Month of Surgery:
01 = January to
12 = December

11

14

1

Geographic Region
1 = Northeast
2 = Midwest
3 = South
4 = West

12

15-16

2

Principal Expected Source of Payment
0 = No Charge
1 = Worker=s Compensation
2 = Medicare
3 = Medicaid
4 = CHAMPUS
5 = Other Government Payments
6 = Blue Cross/Blue Shield
7 = HMO/PPO
8 = Other private or commercial insurance
9 = Self Pay
10 = Other, specified
99 = No expected source of payment

13

17-18

2

Other Additional Source of Payment #1:
Same coding as Principal ESOP

14

19-20

2

Other Additional Source of Payment #2:
Same coding as Principal ESOP

15

21-25

5

Analysis Weight: Use to Obtain Weighted Estimates

16-25

26-35

10

Type of Anesthesia: 10 types/options
1 = Option Checked
0 = Not Checked/Blank

16

26

1

Type of Anesthesia: Topical/Local

17

27

1

Type of Anesthesia: IV Sedation

18

28

1

Type of Anesthesia: Monitored Anesthesia Care

19

29

1

Type of Anesthesia: Regional, Epidural

20

30

1

Type of Anesthesia: Regional, Spinal

21

31

1

Type of Anesthesia Regional, Retrobulbar block

22

32

1

Type of Anesthesia: Regional, Peribulbar block

23

33

1

Type of Anesthesia: Regional, Block

24

34

1

Type of Anesthesia: General

25

35

1

Type of Anesthesia: Other, specified

26-28

36-38

3

Anesthesia Administrator: 3 givers/options
1 = Option Checked
0 = Not checked/Blank

26

36

1

Anesthesia Administrator:
Anesthesiologist

27

37

1

Anesthesia Administrator:
Certified Registered Nurse Anesthetist

28

38

1

Anesthesia Administrator:
Other Surgeon/Physician

29

39-43

5

Diagnosis ICD9-CM ** Code #1

30

44-48

5

Diagnosis ICD9-CM ** Code #2

31

49-53

5

Diagnosis ICD9-CM ** Code #3

32

54-58

5

Diagnosis ICD9-CM ** Code #4

33

59-63

5

Diagnosis ICD9-CM ** Code #5

34

64-68

5

Diagnosis ICD9-CM ** Code #6

35

69-73

5

Diagnosis ICD9-CM ** Code #7

36

74-77

4

Procedure ICD9-CM ** Code #1

37

78-81

4

Procedure ICD9-CM ** Code #2

38

82-85

4

Procedure ICD9-CM ** Code #3

39

86-89

4

Procedure ICD9-CM ** Code #4

40

90-93

4

Procedure ICD9-CM ** Code #5

41

94-97

4

Procedure ICD9-CM ** Code #6

------------------------------------------------------------------------------------------------------------------

* Ages 100 and over were recoded to 99.

** Codes are in compliance with the International Classification of Diseases, 9th Revision, Clinical Modification, (ICD-9-CM). For diagnosis codes, there is an implied decimal between positions 3 and 4. For V-Codes and E-codes, the implied decimal is between positions 4 and 5. For inapplicable 4th or 5th digits, a dash is inserted. For procedure codes, there is an implied decimal between positions 2 and 3. For inapplicable 3rd or 4th digits, a dash is inserted.


APPENDIX A

Definition of  Terms

Hospitals-Short-stay hospitals or hospitals whose specialty is general (medical or surgical), or children's general. Hospitals must have 6 beds or more staffed for patients use. Federal hospitals and hospital units of institutions are not included.

Free-Standing Ambulatory Surgery Centers-Facilities listed in the 1993 Freestanding Outpatient Surgery Center Database and Medicare-certified facilities included in the HCFA Provider-of-Services (POS) file. Facilities specializing in dentistry, podiatry, abortion, family planning, or birthing are excluded.

Ambulatory Surgery-Scheduled outpatient surgery performed in any of the following locations: general or main operating room, satelitte operating room, cystoscopy room, endoscopy room, cardiac catherterization lab, laser procedures room.

First-listed diagnosis-The coded diagnosis which is listed first on the face sheet of the medical record. The number of first-listed diagnoses is equivalent to the number of ambulatory surgery visits.

Procedures-Surgical or nonsurgical operations, procedures, or special treatments listed by the physician on the medical record. In the NSAS, all terms listed on the face sheet (summary sheet) of the medical record under the caption "operation," "operative procedures," "operations and/or special treatment," and the like are transcribed in the order listed. A maximum of six procedures is coded.

Rate of procedures-The ratio of the number of procedures during a year to the number of persons in the civilian population on July 1 of that year.

Age-The age of the patient on the birthday prior to the date of surgery.

Population-Civilian population is the resident population excluding members of the Armed Forces.

Geographic region-Hospitals are classified by location in one of the four geographic regions of the United States corresponding to those used by the U.S. Bureau of the Census:

Geographic Region States included

Northeast.............Maine, New Hampshire, Vermont
                            Massachusetts, Rhode Island,
                            Connecticut, New York, New Jersey,
                            and Pennsylvania

Midwest..............Michigan, Ohio, Illinois, Indiana,
                           Wisconsin, Minnesota, Iowa,
                           Missouri, North Dakota,
                           South Dakota, Nebraska,
                           and Kansas

South..................Delaware, Maryland, District of Columbia,
                           Virginia, West Virginia, North Carolina,
                           South Carolina, Georgia, Florida, Kentucky,
                           Tennessee, Alabama, Mississippi, Arkansas,
                           Louisiana, Oklahoma, and Texas

West...................Montana, Idaho, Wyoming, Colorado,
                           New Mexico, Arizona, Utah, Nevada, Washington,
                           Oregon, California, Hawaii, and Alaska


APPENDIX B

The International Classification of Diseases, 9th Revision, Clinical Modification, which has been used for coding NHDS data since 1979, undergoes annual updating. Assignment of new diagnostic and procedure codes, fourth and fifth digit expansion of codes, as well as code deletions, are contained in addenda developed by the ICD-9-CM Coordination and Maintenance Committee and approved by the Director of NCHS and the Administrator of the Health Care Financing Administration. Addenda to the ICD-9-CM become effective on October 1 of the calendar year and have been released for 1986 through 1995.

As described earlier in this document, the 1995 NSAS involved two data collection modes: manual and abstract service. All data collected manually were coded using the third edition of the ICD-9-CM, which includes the addenda for 1986 through 1994. Data collected via abstract service were coded using two different ICD-9-CM revisions. For the first 9 months of 1995, the ICD-9-CM including the addendum of October 1, 1986-94 was used; for the last 3 months the October 1995 addendum was used. Therefore, data provided by automated systems for the last three months of 1995 was converted back to the code assignment under the October 1994 addendum. This was done in order to prevent NHDS data users from mistaking partial year estimates for annual estimates.

In order to assist users in data retrieval, a conversion table is provided that shows the date of introduction of each new code and the previously assigned code equivalent, which had been used for reporting the selected diagnosis or procedure prior to issuance of the new code.

DIAGNOSES CODES
Current code(s) assignment

Effective October 1

Previous code(s) assignment
008.00-008.09

1992

008.0
008.43-008.47

1992

008.49
008.61-008.69

1992

008.6
041.00-041.09

1992

041.0
041.10-041.19

1992

041.1
041.81-041.89

1992

041.8
042

1994

042.0-042.2,042.9,043.0-043.3,
043.9,044.0,044.9
042.0-042.9

1986

279.19
043.0-043.9

1986

279.19
044.0-044.9

1986

279.19
070.20-070.21

1991

070.2
070.22

1994

070.20
070.23

1994

070.21
070.30-070.31

1991

070.3
070.32

1994

070.30
070.33

1994

070.31
070.41-070.49

1991

070.4
070.44

1994

070.41
070.51-070.59

1991

070.5
070.54

1994

070.51
077.98-077.99

1993

077.9
078.10-078.11,078.19

1993

078.1
078.88

1993

078.89
079.4

1993

079.8
079.50-079.53,079.59

1993

079.8
079.88-079.89

1993

079.8
079.98-079.99

1993

079.9
088.81,088.89

1989

088.8
088.82

1993

088.89
099.40-099.49

1992

099.4
099.50-099.59

1992

078.89
112.84-112.85

1992

112.89
114.4-114.5

1993

114.3
176.0-176.9

1991

173.0-173.9
203.00

1991

203.0
203.01

1991

V10.79
203.10

1991

203.1
203.11

1991

V10.79
203.80

1991

203.8
203.81

1991

V10.79
204.00

1991

204.0
204.01

1991

V10.61
204.10

1991

204.1
204.11

1991

V10.61
204.20

1991

204.2
204.21

1991

V10.61
204.80

1991

204.8
204.81

1991

V10.61
204.90

1991

204.9
204.91

1991

V10.61
205.00

1991

205.0
205.01

1991

V10.62
205.10

1991

205.1
205.11

1991

V10.62
205.20

1991

205.2
205.21

1991

V10.62
205.30

1991

205.3
205.31

1991

V10.62
205.80

1991

205.8
205.81

1991

V10.62
205.90

1991

205.9
205.91

1991

V10.62
206.00

1991

206.0
206.01

1991

V10.63
206.10

1991

206.1
206.11

1991

V10.63
206.20

1991

206.2
206.21

1991

V10.63
206.80

1991

206.8
206.81

1991

V10.63
206.90

1991

206.9
206.91

1991

V10.63
207.00

1991

207.0
207.01

1991

V10.69
207.10

1991

207.1
207.11

1991

V10.69
207.20

1991

207.2
207.21

1991

V10.69
207.80

1991

207.8
207.81

1991

V10.69
208.00

1991

208.0
208.01

1991

V10.60
208.10

1991

208.1
208.11

1991

V10.60
208.20

1991

208.2
208.21

1991

V10.60
208.80

1991

208.8
208.81

1991

V10.60
208.90

1991

208.9
208.91

1991

V10.60
237.70-237.72

1990

237.7
250.02

1993

250.90
250.03

1993

250.91
250.12

1993

250.10
250.13

1993

250.11
250.22

1993

250.20
250.23

1993

250.21
250.32

1993

250.30
250.33

1993

250.31
250.42

1993

250.40
250.43

1993

250.41
250.52

1993

250.50
250.53

1993

250.51
250.62

1993

250.60
250.63

1993

250.61
250.72

1993

250.70
250.73

1993

250.71
250.82

1993

250.80
250.83

1993

250.81
250.92

1993

250.90
250.93

1993

250.91
283.10-283.11,283.19

1993

283.1
305.1

1994

305.10,305.11,305.12,
305.13 (delete code)
320.81-320.89

1992

320.8
312.81-312.82,381.89

1994

312.8
333.92-333.93

1994

333.99
337.20-337.22,337.29

1993

337.5
342.00-342.02

1994

342.0
342.10-342.12

1994

342.1
342.80-342.82

1994

342.9
342.90-342.92

1994

342.9
344.00-344.04,344.09

1994

344.0
344.30-344.32

1994

344.3
344.40-344.42

1994

344.4
344.81-344.89

1993

344.8
345.00-345.01

1989

345.0
345.10-345.11

1989

345.1
345.40-345.41

1989

345.4
345.50-345.51

1989

345.5
345.60-345.61

1989

345.6
345.70-345.71

1989

345.7
345.80-345.81

1989

345.8
345.90-345.91

1989

345.9
346.00-346.01

1992

346.0
346.10-346.11

1992

346.1
346.20-346.21

1992

346.2
346.80-346.81

1992

346.8
346.90-346.91

1992

346.9
355.71

1993

354.4
355.79

1993

355.7
371.82

1992

371.89
374.87

1990

374.89
403.00-403.01

1989

403.0
403.10-403.11

1989

403.1
403.90-403.91

1989

403.9
404.00-404.03

1989

404.0
404.10-404.13

1989

404.1
404.90-404.93

1989

404.9
410.00-410.02

1989

410.0
410.10-410.12

1989

410.1
410.20-410.22

1989

410.2
410.30-410.32

1989

410.3
410.40-410.42

1989

410.4
410.50-410.52

1989

410.5
410.60-410.62

1989

410.6
410.70-410.72

1989

410.7
410.80-410.82

1989

410.8
410.90-410.92

1989

410.9
411.81

1989

410.9
411.89

1989

411.8
414.00-414.01

1994

414.0
414.02-414.03

1994

996.03
429.71

1989

410.0-410.9
429.79

1989

410.0-410.9
433.00-433.01

1993

433.0
433.10-433.11

1993

433.1
433.20-433.21

1993

433.2
433.30-433.31

1993

433.3
433.80-433.81

1993

433.8
433.90-433.91

1993

433.9
434.00-434.01

1993

434.0
434.10-434.11

1993

434.1
434.90-434.91

1993

434.9
437.7

1992

780.9
440.20-440.22

1992

440.2
440.23

1993

440.20 & 707.1 or 707.8 or 707.9
440.24

1993

440.20 & 785.4
440.29

1993

440.20
440.30-440.32

1994

996.1
441.00-441.03

1994

441.0
441.6

1993

441.1 & 441.3
441.7

1993

441.2 & 441.4
446.20-446.21,446.29

1990

446.2
451.82-451.84

1993

451.89
482.30-482.39

1992

482.3
482.81-482.89

1992

482.8
483.0

1992

483
483.8

1992

483
491.20-491.21

1991

491.2
493.20

1989

493.90
493.21

1989

493.91
512.1

1994

997.3
518.81

1987

799.1
518.82-518.89

1987

518.8
524.00-524.09

1992

524.0
524.10-524.19

1992

524.1
524.60-524.69

1991

524.6
524.70-524.79

1992

524.8
530.10-530.11, 530.19

1993

530.1
530.81

1993

530.1
530.82-530.84, 530.89

1993

530.8
535.00-535.01

1991

535.0
535.10-535.11

1991

535.1
535.20-535.21

1991

535.2
535.30-535.31

1991

535.3
535.40-535.41

1991

535.4
535.50-535.51

1991

535.5
535.60-535.61

1991

535.6
536.3

1994

536.8
537.82

1990

537.89
537.83

1991

537.82
556.0-556.6

1994

556
556.8-556.9

1994

556
562.02

1991

562.00
562.03

1991

562.01
562.12

1991

562.10
562.13

1991

562.11
569.84

1990

557.1
569.85

1991

569.84
 

 

 

 

593.70-593.73

1994

593.7
596.51-596.53

1992

596.5
596.54

1992

344.61
596.55-596.59

1992

596.5
599.81-599.89

1992

599.8
645.0

1991

645
651.30-651.31,651.33

1989

651.00-651.01,651.03
651.40-651.41,651.43

1989

651.10-651.11,651.13
651.50-651.51,651.53

1989

651.20-651.21,651.23
651.60-651.61,651.63

1989

651.80-651.81,651.83
654.20-654.21,654.23

1990

654.2,654.9
654.90-654.94

1990

654.2,654.9
657.0

1991

657
659.60,659.61,659.63

1992

659.80,659.81,659.83
665.10,665.11

1992

665.10,665.11,665.12,665.14
Note: The title for the subcategory, 665.1 has been changed,  making the fifth-digit
subclassification, 665.12 and 665.14 invalid.
670.0

1991

670
672.0

1991

672
677

1994

* No previous code assignments.
692.72-692.74

1992

692.79
692.82-692.83

1992

692.89
702.0-702.8

1991

702
702.11,702.19

1994

702.1
704.02

1993

704.09
709.00-709.01,709.09

1994

709.0
710.5

1992

288.3,729.1
733.10-733.16, 733.19

1993

733.1
738.10-738.19

1992

738.1
747.60-747.64, 747.69

1993

747.6
747.82

1993

747.89
753.10-753.17,753.19

1990

753.1
759.81-759.89

1989

759.8
759.83

1994

759.89
760.75

1991

760.79
760.76

1994

760.79
764.00-764.09

1988

764.0
764.10-764.19

1988

764.1
764.20-764.29

1988

764.2
764.90-764.99

1988

764.9
765.00-765.09

1988

765.0
765.10-765.19

1988

765.1
780.01-780.09

1992

780.0
780.03

1993

780.01
780.57

1992

780.51,780.53
781.8

1994

781.9
787.01-787.03

1994

787.0
788.20-788.21, 788.29

1993

788.2
788.30-788.39

1992

788.3
788.40-788.43

1993

788.4
788.61-788.62, 788.69

1993

788.6
789.00-789.07, 789.09

1994

789.0
789.30-789.37, 789.39

1994

789.3
789.40-789.47, 789.49

1994

789.4
789.60-789.67, 789.69

1994

789.6
790.91

1993

790.9
790.92

1993

286.9
790.93, 790.99

1993

790.9
795.71

1994

795.8 (delete code)
795.79

1994

795.7
795.8

1986

795.7
864.05

1992

864.09
864.15

1992

864.19
909.5

1994

909.9
925.1-925.2

1993

925
995.60-995.69

1993

995.0
996.04

1994

996.09
996.51-996.59

1987

996.5
996.60-996.69

1989

996.6
996.70-996.79

1989

996.7
996.80-996.89

1987

996.8
996.85

1990

999.8
998.81-998.82, 998.89

1994

998.8
V03.81-V03.82, V03.89

1994

V03.8
V05.3-V05.4

1993

V05.8
V06.5-V06.6

1994

V06.8
V07.31,V07.39

1994

V07.3
V07.4

1992

V07.8
V08

1994

044.9, 795.8 (delete code)
V09.0-V09.91

1993

* No previous code assignments
V12.00-V12.03, V12.09

1994

V12.0
V12.70-V12.72, V12.79

1994

V12.7
V13.00-V13.01, V13.09

1994

V13.0
V15.82

1994

305.13 (delete code)
V25.43

1992

V25.49
V25.5

1992

V25.8
V29.0-V29.8

1992

V71.8
V29.9

1992

V71.9
V30.00-V30.01

1989

V30.0
V31.00-V31.01

1989

V31.0
V32.00-V32.01

1989

V32.0
V33.00-V33.01

1989

V33.0
V34.00-V34.01

1989

V34.0
V35.00-V35.01

1989

V35.0
V36.00-V36.01

1989

V36.0
V37.00-V37.01

1989

V37.0
V39.00-V39.0l

1989

V39.0
V43.60-V43.66, V43.69

1994

V43.6
V45.00

1994

V45.89
V45.01

1994

V45.0
V45.02, V45.09

1994

V45.89
V45.51

1994

V45.5
V45.52, V45.59

1994

V45.89
V45.82

1994

V45.89
V49.60-V49.67

1994

V49.5
V49.70-V49.77

1994

V49.5
V50.41-V50.42, V50.49

1994

V50.8
V53.31

1994

V53.3
V53.32, V53.39

1994

V53.9
V57.21-V57.22

1994

V57.2
V58.41, V58.49

1994

V58.4
V58.81, V58.89

1994

V58.8
V65.40-V65.45, V65.49

1994

V65.4
V69.0-V69.3

1994

* No previous code assignments.
V69.8-V69.9

1994

* No previous code assignments.
V72.81-V72.85

1993

V72.8
V73.88-V73.89

1993

V73.8
V73.98-V73.99

1993

V73.9
E869.4

1994

E869.8


PROCEDURE   CODES
Current code(s) assignment

Effective October 1

Previous code(s) assignment
02.96

1992

89.19
03.90

1987

03.99 (Insertion of Catheter)
11.75

1989

11.79
11.76

1989

11.62
20.96-20.98

1986

20.95
22.12

1988

22.11
26.12

1988

26.11
29.31

1991

83.02
29.32

1991

29.3
29.33

1991

29.3
29.39

1991

29.3
31.45

1988

31.43-31.44
31.95

1989

31.75
32.01

1989

32.0
32.09

1989

32.0
32.28

1989

32.29
33.27

1987

33.22 + 33.27
33.28

1987

33.27
33.29

1987

33.28-33.29
33.6

1990

33.5 + 37.5
34.05

1994

34.99
35.84

1988

35.82
35.96

1986

35.03
36.00-36.03

1986

36.0
36.04

1986

39.97
36.05

1987

36.01
36.05

1986

36.01 (Before October 1986 contents of current code 36.05 would have been assigned to 36.0), 36.02
36.09

1986

36.0
36.09

1991

36.00 (Code Deleted)
37.26-37.27

1988

37.29
37.34

1988

37.33
37.70 (Leads only)

1987 (Leads/Device)

37.70
37.71-37.72 (Leads only)

1987 (Leads/Device)

37.74
37.73 (Leads only)

1987 (Leads/Device)

37.73
37.74 (Leads only)

1987 (Leads/Device)

37.76
37.75 (Leads only)

1987 (Leads/Device)

37.89
37.76 (Leads only)

1987 (Leads/Device)

37.81
37.77 (Leads only)

1987 (Leads/Device)

37.83-37.84
37.78

1987

37.71-37.72
37.79

1987

86.09
37.80-37.87

1992

89.49 (Code deleted, this procedure is included in the code for pacemaker insertion/replacement)
37.80 (Device only)

1987 (Leads/Device)

37.73-37.77
37.81 (Device only)

1987 (Leads/Device)

37.73-37.77
37.82 (Device only)

1987 (Leads/Device)

37.73-37.77
37.83 (Device only)

1987 (Leads/Device)

37.73-37.77
37.85-37.87

1987

37.85
37.89

1987

37.86 + 37.89
37.94-37.98

1986

37.99
38.22

1986

38.29
38.44 (Abdominal Aorta only)

1986

38.44 (Entire Aorta)
38.45 (Thoracic Aorta only)

1986

38.44-38.45
38.95

1989

38.93
39.28

1991

39.29
39.65

1988

39.61
39.66

1990

39.65
41.00-41.03

1988

41.0
41.04

1994

99.79
42.25

1988

42.24
42.33

1989

42.32, 42.39
42.33

1990

42.91
43.11

1989

43.1
43.19

1989

43.1, 43.2
43.41

1989

43.41,43.49
44.21

1986

44.2
44.22

1986

44.99
44.29

1986

44.2
44.43

1989

43.49,45.32
44.44

1989

38.86
44.49

1989

43.0
44.93-44.94

1986

44.99
45.16

1988

45.14 (45.15 before 1987)
45.30

1989

45.31,45.32
45.42

1988

45.41
45.43

1989

45.49
45.75 (Hartmann Resection Added)

1988

48.66 (Code Deleted)
45.95

1987

45.93
46.13

1992

46.12 (Code Deleted)
46.32

1989

46.39
46.85

1989

46.99
49.31

1989

49.3
49.39

1989

49.3
51.10

1989

51.97
51.11

1989

51.11,51.97
51.14

1989

51.12
51.15

1989

51.97
51.22

1991

51.21 (Code Deleted),51.22
51.23

1991

51.22
51.64

1989

51.69
51.84-51.88

1989

51.97
51.97

1986

52.91,51.99, or 51.82
51.98

1986

51.99
52.13

1989

51.97,52.91
52.14

1989

52.11
52.21

1989

52.2
52.22

1989

52.2
52.93

1989

52.93 + 52.91
52.94

1989

52.09
52.97

1989

52.91
52.98

1989

52.91
52.99

1989

52.93,52.94,52.99
54.24

1987

54.23
54.25

1993

54.98
55.03-55.04

1986

55.02
56.33-56.34

1987

56.33
56.35

1987

45.12
57.17-57.18

1989

57.21
57.22

1989

57.22,57.82
58.31

1990

58.3
58.39

1990

58.3
58.93

1986

57.99
59.96

1986

59.95
60.95

1991

60.99
64.97

1986

64.95
66.01

1992

66.0
66.02

1992

66.73
68.15

1987

68.14
68.16

1987

68.13
68.9

1992

68.4
74.3

1992

69.11 (Code Deleted)
77.56

1989

77.89,78.49,81.18
77.57

1989

77.89,80.48,81.18,83.85
77.58

1989

77.59,81.18
78.10

1991

78.40
78.11

1991

78.41
78.12

1991

78.42
78.13

1991

78.43
78.14

1991

78.44
78.15

1991

78.45
78.16

1991

78.46
78.17

1991

78.47
78.18

1991

78.48
78.19

1991

78.49
78.20

1991

78.10,78.20,78.30
78.21

1991

78.11,78.31
78.22

1991

78.12,78.22,78.32
78.23

1991

78.13,78.23,78.33
78.24

1991

78.14,78.34
78.25

1991

78.15,78.25,78.35
78.27

1991

78.17,78.27,78.37
78.28

1991

78.18,78.38
78.29

1991

78.11,78.16,78.19,78.29,78.39
78.39

1991

78.31
78.90 2/

1987

78.40
78.91 2/

1987

78.41
78.92 2/

1987

78.42
78.93 2/

1987

78.43
78.94 2/

1987

78.44
78.95 2/

1987

78.45
78.96 2/

1987

78.46
78.97 2/

1987

78.47
78.98 2/

1987

78.48
78.99 2/

1987

78.49
80.50-80.59

1986

80.5
81.03

1989

81.02
81.04-81.05

1989

81.03,81.04,81.05
81.06-81.07

1989

81.06,81.07
81.08

1989

81.06,81.07,81.08
81.09

1989

81.08
81.40

1989

81.69
81.51

1989

81.51,81.59
81.52

1989

81.61,81.62,81.63,81.64
81.53

1989

81.51,81.59,81.61,81.62, 81.63, 81.64
81.54-81.55

1989

81.41
81.56

1989

81.48
81.57

1989

81.31,81.39
81.59

1989

81.39
81.72

1989

81.79
81.73-81.74

1989

81.86
81.75

1989

81.87
81.79

1989

81.79,81.87
81.80

1989

81.81
81.97

1992

81.59
85.95

1987

85.99
85.96

1987

85.99
86.06

1987

86.09
86.07

1990

86.09
86.27

1986

86.22-86.23
86.28

1988

86.22
86.93

1987

86.89
88.90

1986

88.39
88.91

1986

89.15
88.92

1986

89.39
88.93

1986

89.15
88.94

1986

89.39
88.95

1986

89.29
88.97

1989

88.99
88.98

1989

88.90
88.99

1986

89.39
89.10

1989

89.15
89.17-89.18

1988

89.15
89.19

1989

89.15
89.50

1991

89.54
93.90

1988

93.92
94.61-94.69

1989

94.25
96.6

1986

96.35
96.70

1991

93.92 (Code Deleted)
96.71

1991

93.92 (Code Deleted)
96.72

1991

93.92 (Code Deleted)
97.05

1989

51.97
98.51-98.52

1989

59.96 (Code Deleted)
98.59

1989

59.96 (Code Deleted)
99.15

1986

99.29
99.28

1994

99.25
99.71-99.79 3/

1988

99.07
99.85

1987

93.35
99.86

1987

93.39
99.88

1988

99.83

1/ Before October 1986 contents of current code 36.05 would have been assigned to 36.0.

2/ Codes 78.90-78.99 were retitled as "Insertion of bone growth stimulator" in October 1987; the previous contents of codes 78.90-78.99 were reassigned to codes 78.40-78.49.

3/ Codes 99.71-99.79 were deleted in October 1987; their contents were not transferred elsewhere. In the October 1988 revision, codes 99.71-99.79 were reclassified as "Therapeutic apheresis."


APPENDIX C

Civilian Population* by Sex, Age, Geographic Region and Race United States, July 1, 1995

[Population estimates consistent with Series P-25,  Current Population Reports, U.S. Bureau of the Census]

Age, geographic region and race
 

 

Both sexes

Male

Female

Population in thousands
All ages

261,407

127,134

134,273

Northeast

51,395

24,751

26,644

Midwest

61,698

30,003

31,695

South

91,143

44,018

47,125

West

57,170

28,361

28,809

White

217,041

106,062

110,979

Black

32,883

15,513

17,370

All other

11,483

5,559

5,924

Under 15 years

57,726

29,554

28,172

Under 1 year

3,848

1,970

1,878

1-4 years

15,743

8,055

7,688

5-14 years

38,134

19,529

18,606

Northeast

10,646

5,452

5,193

Midwest

13,491

6,910

6,581

South

20,027

10,243

9,784

West

13,562

6,948

6,614

White

45,728

23,463

22,264

Black

9,002

4,565

4,437

All other

2,996

1,526

1,470

15-44 years

117,976

58,700

59,276

15-24 years

35,431

17,909

17,522

25-34 years

40,349

19,972

20,377

35-44 years

42,195

20,819

21,377

Northeast

22,896

11,354

11,542

Midwest

27,770

13,835

13,935

South

40,999

20,177

20,823

West

26,311

13,335

12,976

White

96,442

48,412

48,030

Black

15,803

7,506

8,297

All other

5,731

2,782

2,949

45-64 years

52,173

25,192

26,981

45-54 years

31,043

15,149

15,894

55-64 years

21,130

10,043

11,087

Northeast

10,561

5,045

5,516

Midwest

12,344

5,985

6,359

South

18,434

8,837

9,597

West

10,834

5,325

5,509

White

44,817

21,874

22,943

Black

5,358

2,388

2,971

All other

1,998

930

1,068

65 years & over

33,532

13,689

19,844

65-74 years

18,759

8,342

10,417

75-84 years

11,145

4,330

6,815

85 years and over

3,628

1,017

2,611

Northeast

7,293

2,900

4,393

Midwest

8,094

3,273

4,821

South

11,683

4,762

6,921

West

6,462

2,753

3,709

White

30,055

12,313

17,742

Black

2,719

1,055

1,665

All other

758

321

437

*The NHDS used the civilian noninstitutional population to calculate hospital utilization rates from 1965 through 1980. Beginning in 1981, the civilian resident population has been used to calculate rates. If you have purchased NHDS tapes for years before 1981 and calculated rates using the civilian noninstitutionalized population provided in the documentation, these rates will have to be adjusted to be comparable to 1995 rates using the civilian resident population.


Civilian Population of the United States, July 1, 1995. Estimates by Age, Sex, and Region.

Data are consistent with the estimates announced in Census Advisory CB94-43. Methodology is described in
Current Population Report Series P25-1106. Release date 3/15/94

                                                                            Civilian population in thousands

  United States Northeast Midwest South West
AGE TOTAL MALE FEMALE TOTAL MALE FEMALE TOTAL MALE FEMALE TOTAL MALE FEMALE TOTAL MALE FEMALE

ALL

261,407

127,134

134,273

51,395

24,751

26,644

61,698

30,003

31,695

91,143

44,018

47,125

57,170

28,361

28,809

0-4

19,591

10,025

9,566

3,617

1,852

1,765

4,393

2,248

2,145

6,782

3,469

3,314

4,799

2,456

2,342

5-9

19,220

9,843

9,377

3,613

1,853

1,760

4,498

2,305

2,193

6,631

3,390

3,240

4,479

2,295

2,184

10-14

18,915

9,685

9,229

3,416

1,747

1,668

4,601

2,358

2,243

6,614

3,384

3,230

4,285

2,197

2,088

15-19

17,974

9,189

8,785

3,229

1,645

1,583

4,417

2,257

2,160

6,383

3,248

3,134

3,945

2,038

1,908

20-24

17,458

8,720

8,738

3,259

1,627

1,632

4,146

2,070

2,076

6,244

3,066

3,178

3,809

1,957

1,851

25-29

18,721

9,282

9,439

3,733

1,849

1,884

4,267

2,110

2,157

6,457

3,156

3,301

4,264

2,167

2,097

30-34

21,629

10,690

10,938

4,317

2,131

2,186

4,960

2,452

2,508

7,445

3,637

3,808

4,906

2,470

2,436

35-39

22,064

10,906

11,158

4,392

2,167

2,225

5,208

2,588

2,621

7,548

3,685

3,863

4,915

2,466

2,449

40-44

20,132

9,913

10,219

3,967

1,934

2,032

4,771

2,358

2,413

6,922

3,384

3,538

4,472

2,237

2,236

45-49

17,419

8,532

8,887

3,492

1,688

1,804

4,081

2,002

2,079

6,068

2,961

3,108

3,778

1,882

1,896

50-54

13,624

6,617

7,008

2,766

1,328

1,439

3,201

1,557

1,644

4,801

2,318

2,484

2,855

1,414

1,441

55-59

11,084

5,316

5,767

2,239

1,065

1,174

2,655

1,279

1,376

3,949

1,877

2,072

2,241

1,096

1,145

60-64

10,046

4,727

5,320

2,064

965

1,099

2,407

1,147

1,260

3,616

1,681

1,934

1,960

933

1,027

65-69

9,928

4,506

5,422

2,125

951

1,173

2,343

1,072

1,271

3,533

1,594

1,939

1,928

889

1,039

70-74

8,831

3,836

4,995

1,905

811

1,094

2,075

902

1,172

3,109

1,343

1,766

1,742

780

962

75-79

6,681

2,720

3,961

1,466

577

888

1,625

651

974

2,302

937

1,365

1,289

555

734

80-84

4,464

1,609

2,854

984

344

640

1,108

392

716

1,530

548

982

842

326

516

85+

3,628

1,017

2,611

813

217

597

944

256

688

1,209

341

869

662

204

458

0-14

57,726

29,554

28,172

10,646

5,452

5,193

13,491

6,910

6,581

20,027

10,243

9,784

13,562

6,948

6,614

15-44

117,976

58,700

59,276

22,896

11,354

11,542

27,770

13,835

13,935

40,999

20,177

20,823

26,311

13,335

12,976

45-64

52,173

25,192

26,981

10,561

5,045

5,516

12,344

5,985

6,359

18,434

8,837

9,597

10,834

5,325

5,509

15+

203,681

97,581

106,101

40,750

19,299

21,450

48,207

23,093

25,114

71,117

33,776

37,341

43,608

21,413

22,195

45+

85,705

38,881

46,825

17,853

7,945

9,908

20,437

9,258

11,179

30,118

13,599

16,518

17,297

8,078

9,219

65+

33,532

13,689

19,844

7,293

2,900

4,393

8,094

3,273

4,821

11,683

4,762

6,921

6,462

2,753

3,709

75+

14,773

5,347

9,427

3,263

1,138

2,125

3,676

1,299

2,378

5,041

1,825

3,216

2,792

1,084

1,708

Civilian Population of the United States, July 1, 1995. Estimates by Age, Sex, and Race (Consistent with the 1990 Census, as enumerated.)

______________________________________________________________________________________________
                              All Races                               White                                  Black                             Other Races
  Age        Total       Male      Female       Total     Male      Female      Total        Male     Female      Total     Male    Female
______________________________________________________________________________________________
                                                                  Civilian population in thousands

All

261,407

127,134

134,273

217,041

106,062

110,979

32,883

15,513

17,370

11,483

5,559

5,924

0-4

19,591

10,025

9,566

15,451

7,924

7,527

3,100

1,570

1,530

1,040

531

509

0

3,848

1,970

1,878

3,015

1,547

1,467

621

314

307

212

108

104

1

3,840

1,964

1,876

3,028

1,552

1,475

608

307

301

205

105

100

2

3,882

1,990

1,892

3,067

1,575

1,492

611

311

300

204

104

100

3

3,965

2,026

1,939

3,137

1,606

1,531

619

313

305

209

107

103

4

4,056

2,075

1,981

3,205

1,643

1,562

642

325

317

209

107

103

5-9

19,220

9,843

9,377

15,237

7,818

7,418

3,025

1,535

1,491

958

490

468

5

4,039

2,069

1,970

3,198

1,642

1,557

641

325

316

201

103

98

6

3,888

1,991

1,897

3,071

1,575

1,496

625

318

307

192

98

94

7

3,810

1,949

1,861

3,016

1,547

1,470

602

304

298

191

98

93

8

3,616

1,851

1,765

2,876

1,475

1,401

561

285

276

180

92

88

9

3,867

1,983

1,883

3,075

1,580

1,495

597

303

293

195

99

95

10-14

18,915

9,685

9,229

15,040

7,721

7,319

2,877

1,460

1,417

998

505

493

10

3,869

1,985

1,884

3,084

1,586

1,499

588

299

289

197

100

97

11

3,705

1,897

1,808

2,952

1,516

1,436

559

283

276

194

98

95

12

3,778

1,932

1,846

2,998

1,537

1,460

576

292

284

204

103

102

13

3,811

1,949

1,863

3,030

1,553

1,477

580

294

286

202

102

100

14

3,751

1,922

1,829

2,976

1,529

1,447

574

292

283

201

102

99

15-19

17,974

9,189

8,785

14,290

7,328

6,962

2,806

1,418

1,387

878

443

435

15

3,790

1,944

1,846

2,994

1,540

1,454

602

306

296

194

98

96

16

3,627

1,866

1,761

2,877

1,483

1,393

570

291

279

180

91

89

17

3,596

1,852

1,744

2,864

1,479

1,385

556

284

273

176

89

86

18

3,482

1,775

1,708

2,779

1,421

1,358

544

273

271

160

80

79

19

3,479

1,753

1,726

2,777

1,405

1,372

533

264

269

168

84

85

20-24

17,458

8,720

8,738

13,982

7,027

6,955

2,562

1,239

1,322

914

453

461

20

3,477

1,746

1,731

2,786

1,406

1,381

523

257

265

168

83

84

21

3,327

1,666

1,661

2,652

1,334

1,318

501

245

256

174

87

88

22

3,314

1,654

1,660

2,645

1,330

1,316

491

237

254

178

88

90

23

3,493

1,742

1,752

2,797

1,404

1,392

509

244

265

187

93

95

24

3,846

1,911

1,935

3,101

1,553

1,548

538

256

282

207

103

105

25-29

18,721

9,282

9,439

15,186

7,603

7,583

2,536

1,193

1,343

999

486

513

25

3,810

1,894

1,916

3,090

1,549

1,541

514

243

270

207

102

104

26

3,689

1,828

1,861

3,002

1,501

1,501

487

230

257

200

97

103

27

3,663

1,818

1,846

2,967

1,488

1,479

498

234

264

198

96

102

28

3,543

1,752

1,791

2,889

1,443

1,445

472

221

251

182

87

95

29

4,015

1,991

2,025

3,238

1,622

1,616

565

265

299

213

104

109

30-34

21,629

10,690

10,938

17,803

8,898

8,905

2,776

1,285

1,491

1,050

508

542

30

4,161

2,056

2,105

3,397

1,697

1,700

556

258

298

207

100

107

31

4,220

2,085

2,136

3,464

1,730

1,734

547

254

293

210

101

109

32

4,310

2,130

2,181

3,547

1,771

1,776

549

254

295

214

104

110

33

4,380

2,159

2,221

3,628

1,809

1,819

550

253

297

202

97

105

34

4,557

2,261

2,296

3,766

1,890

1,876

574

265

308

217

105

112

35-39

22,064

10,906

11,158

18,319

9,156

9,163

2,749

1,275

1,474

996

476

520

35

4,551

2,255

2,296

3,764

1,885

1,879

576

268

308

211

102

110

36

4,391

2,167

2,224

3,650

1,823

1,828

544

251

294

197

94

103

37

4,451

2,198

2,253

3,699

1,847

1,852

552

255

296

200

96

104

38

4,185

2,064

2,121

3,490

1,740

1,750

513

237

275

182

87

96

39

4,485

2,222

2,263

3,716

1,861

1,855

564

263

301

205

97

108

40-44

20,132

9,913

10,219

16,863

8,400

8,462

2,375

1,096

1,279

894

417

478

40

4,318

2,133

2,186

3,595

1,796

1,799

528

245

284

195

92

103

41

4,110

2,021

2,090

3,440

1,711

1,729

486

224

262

184

86

98

42

3,987

1,961

2,026

3,351

1,666

1,684

459

211

248

178

83

95

43

3,870

1,897

1,973

3,246

1,611

1,635

449

206

244

175

80

94

44

3,846

1,902

1,944

3,231

1,616

1,615

452

210

242

163

76

87

45-49

17,419

8,532

8,887

14,833

7,347

7,486

1,852

844

1,008

734

342

393

45

3,732

1,836

1,896

3,137

1,562

1,575

432

199

233

163

75

88

46

3,550

1,739

1,811

3,012

1,493

1,519

387

176

211

151

70

82

47

3,580

1,749

1,830

3,039

1,502

1,536

387

175

211

154

72

83

48

3,653

1,787

1,866

3,187

1,575

1,612

334

151

183

132

61

70

49

2,904

1,421

1,484

2,458

1,215

1,243

312

142

170

134

64

70

50-54

13,624

6,617

7,008

11,720

5,750

5,971

1,381

619

761

523

248

276

50

2,888

1,407

1,481

2,465

1,214

1,251

302

136

166

121

57

64

51

2,781

1,352

1,429

2,393

1,175

1,218

280

126

154

108

51

57

52

2,913

1,417

1,496

2,536

1,245

1,291

274

123

151

103

48

54

53

2,567

1,243

1,324

2,205

1,079

1,126

267

119

148

95

45

50

54

2,476

1,197

1,278

2,121

1,037

1,084

258

115

143

97

46

51

55-59

11,084

5,316

5,767

9,540

4,625

4,915

1,138

500

638

406

192

214

55

2,312

1,113

1,199

1,967

956

1,011

254

114

141

91

43

48

56

2,315

1,112

1,203

1,996

970

1,026

236

103

134

83

40

43

57

2,291

1,099

1,192

1,969

954

1,015

239

105

133

83

39

44

58

2,029

970

1,058

1,763

852

911

195

85

110

71

33

38

59

2,137

1,023

1,115

1,845

893

952

214

94

120

78

37

42

60-64

10,046

4,727

5,320

8,723

4,152

4,571

988

425

563

334

149

185

60

2,111

997

1,114

1,832

875

958

206

89

118

72

33

39

61

1,934

918

1,016

1,678

806

873

189

82

107

67

30

37

62

1,939

912

1,027

1,672

796

876

199

86

113

68

30

38

63

1,968

926

1,042

1,717

818

899

188

81

108

62

27

35

64

2,095

975

1,120

1,823

858

965

205

88

117

66

29

37

65-69

9,928

4,506

5,422

8,726

3,993

4,733

920

393

527

282

119

162

65

2,067

959

1,108

1,799

844

954

205

87

118

63

27

36

66

2,010

923

1,087

1,761

814

947

192

84

107

58

24

33

67

2,041

930

1,110

1,796

827

968

189

80

109

56

23

32

68

1,913

856

1,056

1,691

762

929

169

72

97

52

22

30

69

1,897

837

1,060

1,679

745

934

165

70

96

52

22

30

70-74

8,831

3,836

4,995

7,918

3,462

4,456

697

280

416

216

94

122

70

1,884

829

1,055

1,677

743

934

157

64

93

49

21

28

71

1,822

797

1,025

1,634

720

914

143

57

86

45

20

25

72

1,762

769

993

1,578

693

885

138

56

82

46

20

26

73

1,712

736

976

1,543

667

875

130

52

78

39

17

22

74

1,652

705

947

1,487

638

848

129

51

78

37

16

21

75-79

6,681

2,720

3,961

6,039

2,470

3,569

510

194

316

132

56

77

75

1,512

635

877

1,358

573

785

122

49

73

32

14

19

76

1,405

583

821

1,272

530

741

105

42

63

28

11

16

77

1,312

532

780

1,189

485

704

97

37

61

25

11

15

78

1,264

504

760

1,146

460

686

94

34

60

24

10

14

79

1,189

466

723

1,074

422

652

91

34

58

23

10

13

80-84

4,464

1,609

2,854

4,069

1,469

2,600

318

107

211

76

33

44

80

1,076

409

668

981

374

607

76

26

50

19

8

11

81

976

361

616

890

330

560

70

24

46

16

7

9

82

895

321

574

815

293

522

65

22

43

15

6

9

83

801

280

521

734

256

478

54

18

35

13

6

8

84

715

239

476

649

216

433

54

17

37

12

5

7

85+

3,628

1,017

2,611

3,303

919

2,385

274

79

195

51

19

32

0-14

57,726

29,554

28,172

45,728

23,463

22,264

9,002

4,565

4,437

2,996

1,526

1,470

15-44

117,976

58,700

59,276

96,442

48,412

48,030

15,803

7,506

8,297

5,731

2,782

2,949

45-64

52,173

25,192

26,981

44,817

21,874

22,943

5,358

2,388

2,971

1,998

930

1,068

15+

203,681

97,581

106,101

171,314

82,599

88,715

23,881

10,949

12,932

8,487

4,033

4,454

45+

85,705

38,881

46,825

74,872

34,187

40,685

8,078

3,443

4,635

2,756

1,251

1,504

65+

33,532

13,689

19,844

30,055

12,313

17,742

2,719

1,055

1,665

758

321

437

75+

14,773

5,347

9,427

13,411

4,858

8,553

1,102

381

721

260

107

152


APPENDIX D

Unweighted and Weighted Estimates For Selected NSAS Variables 

                                               UNWEIGHTED N       WEIGHTED ESTIMATE

YEAR OF SURGERY 
95                                                    121,564                         19,959,255

FACILITY TYPE
1                                                        73,995                          16,726,675
2                                                          7,569                            3,232,580

AGEUNITS
1                                                      119,938                          19,788,501
2                                                          1,567                               160,458
3                                                               59                                 10,296

AGEFLAG
1                                                             815                               122,712
2                                                      120,749                          19,836,543

SEX
1                                                        52,746                            8,674,346
2                                                        68,818                          11,284,909

SEXFLAG
1                                                          1,274                               143,213
2                                                      120,290                          19,816,042

RACE
1                                                        61,911                          11,955,685
2                                                          6,007                            1,082,836
3                                                             223                                 48,042
4                                                          1,611                               186,576
5                                                          1,205                               136,397
9                                                        50,607                            6,549,719

STATUS AT DISPOSITION
1                                                      110,390                          17,871,611
2                                                          2,903                               648,098
3                                                          1,637                               210,314
4                                                          1,430                               320,946
5                                                             160                                 26,768
6                                                             828                               148,756
9                                                          4,216                               732,762

MONTH OF SURGERY
01                                                        9,899                            1,629,814
02                                                        9,473                            1,571,370
03                                                      10,993                            1,809,082
04                                                        9,621                            1,556,813
05                                                      10,725                            1,730,103
06                                                      10,799                            1,797,695
07                                                        9,386                            1,512,699
08                                                      10,948                            1,767,936
09                                                        9,587                            1,584,050
10                                                      10,283                            1,704,943
11                                                      10,448                            1,714,100
12                                                        9,402                            1,580,650

REGION
1                                                        25,562                            4,506,940
2                                                        27,687                            4,994,613
3                                                        44,263                            6,782,334
4                                                        24,052                            3,675,368

                                              UNWEIGHTED N                WEIGHTED ESTIMATE

PRINCIPAL EXPECTED SOURCE OF PAYMENT
00                                                           760                                         88,614
01                                                        2,867                                       461,431
02                                                      38,690                                    6,122,975
03                                                        8,640                                    1,227,583
04                                                           566                                         82,048
05                                                          984                                        151,321
06                                                     13,819                                     2,514,622
07                                                     17,110                                     3,109,001
08                                                     26,346                                     4,107,608
09                                                       3,416                                        470,899
10                                                       1,845                                        408,417
12                                                       6,521                                     1,214,736

OTHER EXPECTED SOURCE OF PAYMENT 1
00                                                           64                                             5,845
01                                                           44                                           11,266
02                                                         816                                         147,887
03                                                      4,214                                         585,311
04                                                         257                                           43,466
05                                                         512                                           74,509
06                                                      9,827                                      1,558,267
07                                                      1,488                                         281,773
08                                                    13,521                                      2,073,054
09                                                      3,056                                         366,744
10                                                             9                                             4,044

MISSING                                        87,756                                   14,807,089

OTHER EXPECTED SOURCE OF PAYMENT 2
00                                                           12                                            2,425
02                                                             6                                               429
03                                                           12                                            1,935
04                                                             8                                            1,149
05                                                           49                                            2,105
06                                                           71                                          10,489
07                                                           27                                           7,426
08                                                         191                                         32,744
09                                                         671                                         61,915
10                                                           49                                         15,984

MISSING                                      120,468                                  19,822,654




This page last reviewed: Thursday, January 28, 2016
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