1994 NATIONAL HEALTH INTERVIEW SURVEY 04/15/2008 PUBLIC USE DATA RELEASE * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * WARNING - DATA USE RESTRICTIONS! Read Carefully before Using The Public Health Service Act (Section 308 (d)) provides that the data collected by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC), may be used only for the purpose of health statistical reporting and analysis. Any effort to determine the identity of any reported case is prohibited by this law. NCHS does all it can to assure that the identity of data subjects cannot be disclosed. All direct identifiers, as well as any characteristics that might lead to identification, are omitted from the data files. Any intentional identification or disclosure of a person or establishment violates the assurances of confidentiality given to the providers of the information. Therefore, users will: 1. Use the data in these data files for statistical reporting and analysis only. 2. Make no use of the identity of any person or establishment discovered inadvertently and advise the Director, NCHS, of any such discovery (301-458-4000). 3. Not link these data files with individually identifiable data from other NCHS or non-NCHS data files. By using these data, you signify your agreement to comply with the above-stated statutorily based requirements. INTRODUCTION The National Health Interview Survey (NHIS) is conducted annually by the National Center for Health Statistics, Centers for Disease Control and Prevention (CDC). The NHIS administers face-to-face interviews in a nationally representative sample of households. Each week a probability sample of the civilian non- institutionalized population of the United States is interviewed by personnel of the U.S. Bureau of the Census. Information is obtained about the health and other characteristics of each member of the household. The NHIS includes a basic questionnaire that remains the same each year plus one or more additional questionnaires that change periodically. More information on the survey in general and the 1994 version, in particular, is found in the Current Estimates Series report: http://www.cdc.gov/nchs/data/series/sr_10/sr10_193acc.pdf NOTES TO USERS Disability questionnaires were administered in both 1994 and 1995. Information about the same person is found on all files. Each file can be linked by using the unique identification number assigned to each person which is found in locations 5-16 on each file. Both 1994 and 1995 NHIS included the Phase 1 of the Disability supplement (NHIS-D). NHIS-D included two household interviews: in Phase 1 all members of sample families were screened for any indication of disability; in Phase 2 persons with any indication of disability were followed-up for additional information. Phase 1 interviews were conducted in calendar years 1994 and 1995; Phase 2 interviews were usually conducted 6-8 months after the Phase 1 interviews but some were not completed until early 1997. The data from the 1995 Phase 1 interviews and their Phase 2 follow-up interviews are in the 1995 NHIS files except for Polio for which both 1994 and 1995 interviews are found in the 1994 DFS Polio file. Users are advised to subscribe to the NHIS Listserv to receive notice of any corrections/updates. For information about joining the Listserv, see the CONTACT INFORMATION section at the bottom of this document. 1994 NHIS FILES AND DOCUMENTATION The 1994 NHIS files and related documentation have been previously distributed via various formats -- magnetic tape, ASCII CDs, SETS CDs, etc. The files listed below comprise the 1994 National Health Interview Survey (NHIS) public use data release as found on the Internet. A copy of this file (README.TXT) is located in ASCII format at the following ftp location: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1994 1994 NHIS DATA FILES Five 1994 NHIS files are referred to as "core" files because they were administered each year (through 1996) without major modification. The five core files are Household, Person, Condition, Doctor Visit, and Hospital. The 1994 NHIS data have been divided into nineteen data files, consisting of the five core files and fourteen supplemental files. In addition, in 2008, a file containing additional imputation flags for the 1994 Family Resources supplement was released. For ease of transmission, each of the 1994 NHIS data files has been converted into a self-extracting compressed format. To load and expand a compressed file into an ASCII file, perform the following steps: Download a compressed file onto your hard drive into an appropriate directory (folder). For example: Copy the data file HOUSEHLD.EXE into a directory called NHIS1994. To do this, create a directory on your C: drive called NHIS1994. Then, using your browser, go to the FTP site containing the 1994 NHIS data files (see address at end of this section). Right click on the HOUSEHLD.EXE file. Depending on your browser, select Save Link As... or Save Target As... Type c:\nhis1994\HOUSEHLD.EXE in the box labeled File Name and hit Enter. To then extract HOUSEHLD.EXE into the ASCII file HOUSEHLD.DAT, go to the directory NHIS1994 and do the following: - From DOS - in the c:\nhis1994 directory, type HOUSEHLD and hit Enter - From Windows - Double-click on HOUSEHLD.EXE or Click the Start Button, Click Run, enter c:\nhis1994\HOUSEHLD.EXE and hit Enter. The ASCII file HOUSEHLD.DAT will be generated which can then be used for processing by PC statistical software packages which utilize ASCII formatted input, or transferred to another computer for processing. NOTE: The 1994 NHIS files are large in size. Please use caution and check your disk drive capacity before extracting. 1994 NHIS DATA FILES RECORD NHIS FILE TYPE FILE NAME LENGTH # RECS ------------------- ------------ ------ ------- HOUSEHOLD HOUSEHLD.DAT 335 48,584 PERSON PERSONSX.DAT 335 116,179 CONDITION CONDITON.DAT 335 89,199 DOCTOR VISIT DRVISITX.DAT 335 27,366 HOSPITAL HOSPITAL.DAT 335 11,811 ACCESS TO CARE ACCESSXX.DAT 400 116,179 AIDS K AND A AIDSKNOW.DAT 480 19,127 DISABILITY COND DIS1COND.DAT 473 44,453 DISABILITY PERS DIS1PERS.DAT 1660 107,469 DISAB2 ADULT DFSADULT.DAT 3400 16,114 DISAB2 CHILD DFSCHILD.DAT 1860 4,296 DISAB2 OU POLIO OUTCOMEP.DAT 18 202,560 DISAB2 OUTCOME OUTCOMEX.DAT 18 107,469 DISAB2 POLIO DFSPOLIO.DAT 670 566 DISAB2 SOA SOA2PUXX.DAT 1846 9,447 FAMILY RESOURCE FAMLYRES.DAT 594 116,179 HEALTH INSURANC HEALTHIN.DAT 500 116,179 IMMUNIZATION IMMUNIZE.DAT 620 8,087 YEAR 2000 OBJ YEAR2000.DAT 630 19,738 FAM RES - FLAGS FLGNEW94.DAT 105 116,179 Notes: The above data files are the unzipped files in ASCII format. The 1994 NHIS Disability Phase 2 Polio file contains data for both 1994 and 1995. The 1994 NHIS data files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS/1994 1994 NHIS FILE LAYOUTS (CODEBOOKS) There is a file layout (also called codebook or data dictionary) for with each data file. The file layouts are in PDF format and can be viewed with Adobe Acrobat software. The Adobe Acrobat Reader software can be downloaded from the Adobe Acrobat Web site at: http://www.adobe.com/products/acrobat/readstep2.html File File Name Description of Component Format ACCESSXX.PDF Access to Care file layout Adobe PDF AIDSKNOW.PDF AIDS Knowledge and Attitudes file layout Adobe PDF DFSADULT.PDF Disability Phase 2 Adult file layout Adobe PDF DFSCHILD.PDF Disability Phase 2 Child file layout Adobe PDF DFSPOLIO.PDF Disability Phase 2 Polio file layout Adobe PDF DIS1COND.PDF Disability Phase 1 Condition file layout Adobe PDF DIS1PERS.PDF Disability Phase 1 Person file layout Adobe PDF FAMLYRES.PDF Family Income file layout Adobe PDF HEALTHIN.PDF Health Insurance file layout Adobe PDF IMMUNIZE.PDF Immunization file layout Adobe PDF NHISCORE.PDF Core* files layout Adobe PDF OUTCOMEP.PDF Disab. Phase 2 Polio Outcome file layout Adobe PDF OUTCOMEX.PDF Disability Phase 2 Outcome file layout Adobe PDF SOA2PUXX.PDF Disab Phase 2 Supp. on Aging file layout Adobe PDF YEAR2000.PDF Year 2000 Objectives file layout Adobe PDF FREQ1994.PDF Fam. Res. - Added imp. flags Adobe PDF (frequencies) LAYOUT94.PDF Fam. Res. - Added imp. flags Adobe PDF (file layout) READMEFR.PDF Fam. Res. - Added imp. flags Adobe PDF (readme file) *Note: NHISCORE.PDF contains the file layouts for the following five core files: Household, Person, Condition, Doctor Visit, and Hospital. The 1994 NHIS data file layout documentation files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHIS/1994 1994 NHIS SAS INPUT STATEMENTS Sample SAS programs containing input statements have been provided for each data file. By using the ASCII data files (.DAT files) as input to these programs, SAS data files can be created. The SAS input statement programs are stored in ASCII format. File File Name Description of Component Format HOUSEHLD.SAS Household file SAS program ASCII PERSONSX.SAS Person file SAS program ASCII CONDITON.SAS Condition file SAS program ASCII DRVISITX.SAS Doctor Visit file SAS program ASCII HOSPITAL.SAS Hospital file SAS program ASCII ACCESSXX.SAS Access to Care SAS program ASCII AIDSKNOW.SAS AIDS Knowl. & Att. SAS program ASCII DFSADULT.SAS Disab. Ph. 2 Adult SAS pgm ASCII DFSCHILD.SAS Disab. Ph. 2 Child SAS pgm ASCII DFSPOLIO.SAS Disab. Ph. 2 Polio SAS pgm ASCII DIS1COND.SAS Disab. Ph. 1 Condition SAS pgm ASCII DIS1PERS.SAS Disab. Ph. 1 Person SAS pgm ASCII FAMLYRES.SAS Family Income SAS program ASCII HEALTHIN.SAS Health Insurance SAS program ASCII IMMUNIZE.SAS Immunization SAS program ASCII OUTCOMEP.SAS Disab. Ph. 2 Polio Outc. SAS pgm ASCII OUTCOMEX.SAS Disab. Ph. 2 Outcome SAS pgm ASCII SOA2PUXX.SAS Disab. Ph. 2 SOA SAS pgm ASCII YEAR2000.SAS Year 2000 Objectives SAS pgm ASCII FLGNEW94.SAS Fam. Res. - Added imp. flags ASCII The 1994 NHIS sample SAS input statement programs are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1994 1994 NHIS SURVEY QUESTIONNAIRES AND FLASHCARDS The 1994 NHIS questionnaires and flashcards can be found as an appendix to the 1994 Current Estimates publication which is on the internet at: http://www.cdc.gov/nchs/data/series/sr_10/sr10_193acc.pdf MISCELLANEOUS All information collected in the survey is from reports by responsible family members residing in the household. When possible, all adult family members participate in the interview. However, proxy responses are accepted for family members who are not at home and are required for all children and for family members who are physically or mentally incapable of responding for themselves. Although a considerable effort is made to ensure accurate reporting, the information from both proxy respondents and self-respondents may be inaccurate because the respondent is unaware of relevant information, has forgotten it, does not wish to reveal it to an interviewer, or does not understand the intended meaning of a question. Data from the special health topics (supplements) and core in 1994 were collected for 50 weeks. The first two weeks of the year were used for interviewer training. The sample for the NHIS is redesigned every decade using population data from the most recent decennial census. A redesigned sample was implemented in 1995, so the sample design for 1995 is different from the sample designs in 1994 and earlier years of the NHIS. ADDITIONAL INFORMATION ON 1994-1995 NHIS POLIO In 1994 and 1995, the National Health Interview Survey (NHIS) conducted a Disability Followback Survey (DFS) based on responses to a Disability Phase 1 Supplement. There were four DFS questionnaires: one for adults with a past history of Polio; one for children and one for adults with an indication disability; and one for elderly persons 69 years of age and older without any indication of disability, called the Supplement on Aging or SOA. The Polio, DFS-Child, and DFS-Adult questionnaires were fielded in 1994 and 1995. The Polio Questionnaire collected extensive information about the symptoms and impact of the illness at the time of initial diagnosis of polio and at various times after the diagnosis. This includes questions on periods of rehabilitation, post-polio syndrome, times when respondents felt they were at their "physical best", and other health problems experienced. Whenever possible, self response by the polio survivor was required for this component. Users should note that because of the small sample sizes, many single year estimates will not be reliable and variance estimators will be unstable. It is recommended that separate year analyses not be done. Thus, description of several important aspects of the file are found in the file documentation. Data users should use great care in reading all preliminary notes and information in the file documentation. Overview of the 1994-95 NHIS Polio Data File The 1994-1995 NHIS Polio public use data file contains 566 records with a record length of 670. Each record contains data for one person. The contents of the file are described in detail in the file documentation which includes unweighted frequencies for each variable. In general, the 1994-1995 NHIS Polio file is organized in the following manner: a. The NHIS person record from the core questionnaire (locations 1-189); b. The weight and design fields (locations 190-388); c. Polio data fields (locations 389-670); The 1994-1995 NHIS Polio Outcome Data File The Polio Outcome File identifies response or non-response for each adult identified as eligible for the Polio questionnaire in Phase II, and provides a code which indicates the type of outcome that resulted from following-up with eligible respondents. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * CONTACT INFORMATION Updates about new data releases, publications, or errors will be sent to members of the NHIS Listserv. To join, visit the CDC website at: http://www.cdc.gov/nchs/about/major/nhis/nhislist.htm For additional information on the NHIS, visit the website at: http://www.cdc.gov/nchs/nhis.htm If you have questions or comments on any aspect of the NHIS, please contact us: E-mail : nhislist@cdc.gov Call : 301-458-4901 FAX : 301-458-4035 Mail : DHHS:PHS:CDC:NCHS:DHIS 3311 Toledo RD Room 2217 Hyattsville MD 20782 Home Page: http://www.cdc.gov/nchs/nhis.htm For additional information on NCHS data products, contact the: Data Dissemination Branch, NCHS 3311 Toledo Road Hyattsville, MD 20782 Tel: 1-301-458-4636 or 1-866-441-NCHS E-mail: nchsquery@cdc.gov Internet: http://www.cdc.gov/nchs/ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * STATEMENT OF AUTHENTICITY This material has been cleared for public distribution by CDC/ATSDR and will be authentic if obtained directly from ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/. CDC/ATSDR takes all effort to assure the authenticity of electronically distributed documents. However, in all instances where the electronic and official agency record differ, the authenticity of the official agency record is controlling. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *