1996 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. NOTES TO USERS 1996 was the last year in which the NHIS utilized a paper form of questionnaire. Beginning with the next year of the survey, the NHIS was administered via CAPI (computer assisted personal interviewing. 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. 1996 NHIS FILES AND DOCUMENTATION The 1996 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 1996 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/1996 1996 NHIS DATA FILES Five 1996 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 1996 NHIS data have been divided into nine data files, consisting of the five core files and four supplemental files. In addition, in 2008, a file containing additional imputation flags for the 1996 Family Resources supplement was released. For ease of transmission, each of the 1996 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 NHIS1996. To do this, create a directory on your C: drive called NHIS1996. Then, using your browser, go to the FTP site containing the 1996 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:\nhis1996\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 NHIS1996 and do the following: - From DOS - in the c:\nhis1996 directory, type HOUSEHLD and hit Enter - From Windows - Double-click on HOUSEHLD.EXE or Click the Start Button, Click Run, enter c:\nhis1996\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 1996 NHIS files are large in size. Please use caution and check your disk drive capacity before extracting. 1996 NHIS DATA FILES RECORD NHIS FILE TYPE FILE NAME LENGTH # RECS ------------------- ------------ ------ ------- HOUSEHOLD HOUSEHLD.DAT 360 25,990 PERSON PERSONSX.DAT 360 63,402 CONDITION CONDITON.DAT 360 44,357 DOCTOR VISIT DRVISITX.DAT 360 14,024 HOSPITAL HOSPITAL.DAT 360 6,103 ACCESS TO CARE ACCESSXX.DAT 440 63,402 FAMILY RESOURCE FAMLYRES.DAT 655 63,402 HEALTH INSURANC HEALTHIN.DAT 560 63,402 IMMUNIZATION IMMUNIZE.DAT 620 4,464 FAM RES - FLAGS FLGNEW96.DAT 105 63,402 Notes: The Family Resources (Income) file FAMLYRES.EXE had previously been released on the Internet as file 96incpub.exe The above data files are the unzipped files in ASCII format. The 1996 NHIS data files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS/1996 1996 NHIS FILE LAYOUTS (CODEBOOKS) There is a data file layout (also called codebook or data dictionary) associated 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 NHISCORE.PDF Core files layout Adobe PDF ACCESSXX.PDF Access to Care 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 FREQ1996.PDF Fam. Res. - Added imp. flags Adobe PDF (frequencies) LAYOUT96.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 1996 NHIS data file layout documentation files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHIS/1996 1996 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 FAMLYRES.SAS Family Income SAS program ASCII HEALTHIN.SAS Health Insurance SAS program ASCII IMMUNIZE.SAS Immunization SAS program ASCII FLGNEW96.SAS Fam. Res. - Added imp. flags ASCII The 1996 NHIS sample SAS input statement programs are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1996 1996 NHIS SURVEY QUESTIONNAIRES and FLASHCARDS The 1996 NHIS questionnaires are broken into four components. The flashcards were handed to the respondents to facilitate their ability to answer certain questions - these are referenced in the questionnaires. The survey questionnaires and flashcards are in PDF format. File File Name Description of Component Format QNHISCOR.PDF Core Questionnaire PDF QACCESSS.PDF Access to Care Questionnaire PDF QHEALTHN.PDF Health Insurance Questionnaire PDF QIMMUNIZ.PDF Child Immunization Questionnaire PDF FLASHCRD.PDF Flashcards PDF The survey questionnaires and flashcards are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Survey_Questionnaires/NHIS/1996 MISCELLANEOUS Four of the 1996 questionnaires asked questions about each member of every sample family (basic questionnaire or "Core," Access to Care, Family Resources (Income), and Health Insurance), and one asked questions about preschool aged children (Immunization). 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. The components of these locations are of the same field structure as the 1995 files. 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 1996 were collected for 50 weeks. Two weeks were used as interviewer training weeks. Part of the 1996 NHIS sample was used to test the redesigned NHIS CAPI (Computer Assisted Personal Interview) questionnaire that was implemented for the 1997 NHIS. Data collected with the 1996 NHIS CAPI questionnaire was not released. Relative to 1995, the 1996 sample size is reduced by approximately 25% in the first and second quarters, and by approximately 50% in the third and fourth quarters. The interviewed sample for 1996 consisted of 24,371 households containing 63,402 persons. The total noninterview rate was 6.2 percent: 4.1 percent was the result of respondent refusal, and the remainder was primarily the result of failure to locate an eligible respondent at home after repeated calls. 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 1996 is different from the sample designs in 1994 and earlier years of the NHIS. This new design includes a greater number of primary sampling units (PSU's) (from 198 in 1994 to 358 for the 1995 design), and a more complicated nonresponse adjustment based on household screening and oversampling of black and Hispanic persons for more reliable estimates of these groups. Additionally, the 1996 population estimates were adjusted to the national population estimates by age, sex, and race/ethnicity, based on projections from the 1990 U.S. Census. Users who combine data from the 1996 NHIS with NHIS data from earlier years must use a modified SUDAAN procedure for estimating sampling errors. 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 For assistance with the 1996 NHIS, call 301-458-4901 or send an E-mail to NHISLIST@CDC.GOV For additional information on NCHS data products, contact the: Data Dissemination Branch, NCHS 3311 Toledo Road Hyattsville, MD 20782 Tel: (301) 458-4636 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. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *