1968 NATIONAL HEALTH INTERVIEW SURVEY 03/24/2008 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 plus one or more additional questionnaires. More information on the survey in general and the 1968 version, in particular, is found in the Current Estimates Series report: http://www.cdc.gov/nchs/data/series/sr_10/sr10_060acc.pdf NOTES TO USERS 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. 1968 NHIS FILES AND DOCUMENTATION The 1968 NHIS files and related documentation have not been previously distributed. The files listed below comprise the 1968 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/Dataset_Documentation/NHIS/1968/ 1968 NHIS DATA FILES 1968 was a transition for the NHIS from fiscal year (July 1 to June 30) to calendar year. The 1968 NHIS files include both fiscal year files and calendar year files, with some overlap between corresponding fiscal year and calendar year files. During the fiscal year, the NHIS sample was split and two types of questionnaires were administered to approximately half of the overall sample: the "condition approach" questionnaire and the "person approach" questionnaire. During the second half of calendar year 1968, the entire NHIS sample was interviewed using the person approach questionnaire. During this time period, five NHIS files are referred to as "core" files because they were administered each year (through 1996). The five core files are Household, Person, Condition, Doctor Visit, and Hospital. No evidence of a fiscal year Household file was found, and the existing calendar year Household file had too many anomalies to be included in this release. Thus, this release consists of fiscal year and calendar year versions of four out of the five core files, and three supplement files, for a total of eleven files. For ease of transmission, each of the 1968 NHIS data files is available both in a compressed format (.ZIP file extension) and a (Microsoft Windows only) self-extracting compressed format (.EXE file extension). 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 PERSONC.ZIP or PERSONC.EXE into a directory called NHIS1968. To do this, create a directory in an area of your hard drive where you have read/write privilege called NHIS1968 (e.g., C:\NHIS1968 for Microsoft Windows, /home//NHIS1968 for UNIX-like systems). Then, using your browser, go to the FTP site containing the 1968 NHIS data files (see address at end of this section). Right click on the PERSONC.ZIP or PERSONC.EXE file. Depending on your browser, select Save Link As... or Save Target As... and specify the appropriate location for saving the file. Use the system's graphical file system browser (e.g., Microsoft Windows Explorer) to navigate to the file location. All contemporary operating systems have utilities to extract data from .ZIP files. For example, right clicking on PERSONC.ZIP on a Microsoft Windows system will open a dialog box that includes the choice "Extract All...". A self-extracting .EXE file can be activated on a Microsoft Windows system by double-clicking on the file. The ASCII file PERSONC.DAT will be generated with carriage return/line feed characters at the end of each record 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 1968 NHIS files are large in size. Please use caution and check your disk drive capacity before extracting. 1968 NHIS DATA FILES (c) denotes calendar year, (f) denotes fiscal year RECORD NHIS FILE TYPE FILE NAME LENGTH # RECS ------------------- ------------ ------ ------- PERSON (c) PERSONC.DAT 156 132,898 PERSON (f) PERSONF.DAT 156 139,294 CONDITION (c) CONDITIONC.DAT 156 88,086 CONDITION (f) CONDITIONF.DAT 156 114,920 HOSPITAL (c) HOSPITALC.DAT 156 16,873 HOSPITAL (f) HOSPITALF.DAT 156 17,920 DOCTOR VISIT (c) DRVISITC.DAT 156 145,155 DOCTOR VISIT (f) DRVISITF.DAT 156 138,434 MOTOR VEHICLE PERSON ACCIDENT (c) MVPACDNTC.DAT 166 929 MOTOR VEHICLE PERSON ACCIDENT (f) MVPACDNTF.DAT 166 890 HOME CARE (f) HOMECAREF.DAT 156 1,213 Note: The above data files are the unzipped files in ASCII format. The 1968 NHIS data files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS/1968 1968 NHIS FILE LAYOUTS (CODEBOOKS) (c) denotes calendar year, (f) denotes fiscal year There is a file layout (also called codebook or data dictionary) for 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 PERSONC.PDF Person file record layout (c) Adobe PDF PERSONF.PDF Person file record layout (f) Adobe PDF CONDITIONC.PDF Condition file record layout (c) Adobe PDF CONDITIONF.PDF Condition file record layout (f) Adobe PDF HOSPITALC.PDF Hospital file record layout (c) Adobe PDF HOSPITALF.PDF Hospital file record layout (f) Adobe PDF DRVISITC.PDF Doctor Visit file record layout (c) Adobe PDF DRVISITF.PDF Doctor Visit file record layout (f) Adobe PDF MVPACDNTC.PDF Motor Vehicle Person Accident record layout (c) Adobe PDF MVPACDNTF.PDF Motor Vehicle Person Accident record layout (f) Adobe PDF HOMECAREF.PDF Home Care file record layout (f) Adobe PDF OTHER 1968 NHIS DOCUMENTATION NHIS_DIAGNOSTIC_RECODE_x.PDF, x=1 to 4 Adobe PDF Diagnostic recodes 1, 2, 3, 4 (Condition, Hospital files) DIAGRECODE2SUMMARY.PDF Adobe PDF Diagnostic recode 2 summary (Condition files) 68OCCUPATIONRECODES.PDF Adobe PDF Occupation recodes 68INDUSTRYRECODES.PDF Adobe PDF Industry recodes 68SYMPTONS.PDF Adobe PDF Symptom list (Condition files) 68CLASSOFACCIDENTRECODE.PDF Adobe PDF Class of accident recode (Condition files) NHIS1968_NOTES.PDF Adobe PDF General notes about this release 1968_CE_TABLES_TABULATION_EXAMPLES.PDF Adobe PDF Guidance for re-creating selected estimates in the 1968 NHIS Current Estimates report NHIS_HOMECARE_SUPPLEMENT_DIAGNOSTIC_RECODES.PDF Adobe PDF Diagnotic recodes in Home Care file The 1968 NHIS data file layout and other documentation files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHIS/1968 1968 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 CONDITIONC.SAS Condition file (c) SAS program ASCII CONDITIONF.SAS Condition file (f) SAS program ASCII DRVISITC.SAS Doctor Visit file (c) SAS program ASCII DRVISITF.SAS Doctor Visit file (f) SAS program ASCII HOSPITALC.SAS Hospital file (c) SAS program ASCII HOSPITALF.SAS Hospital file (f) SAS program ASCII PERSONC.SAS Person file (c) SAS program ASCII PERSONF.SAS Person file (f) SAS program ASCII MVPACDNTC.SAS Motor Vehicle Person Accident file (c) SAS program ASCII MVPACDNTF.SAS Motor Vehicle Person Accident file (f) SAS program ASCII HOMECAREF.SAS Home Care file (f) SAS program ASCII The 1968 NHIS sample SAS input statement programs are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1968 1968 NHIS SURVEY QUESTIONNAIRES AND FLASHCARDS One of the 1968 NHIS person approach questionnaires, dated 4-25-68, can be found as appendix III to the 1968 Current Estimates publication which is on the Internet at: http://www.cdc.gov/nchs/data/series/sr_10/sr10_060acc.pdf This questionnaire was used during the July-December 1968 period. Another of the 1968 NHIS person approach questionnaires, dated 5-19-67, can be found as appendix IV to an NCHS publication titled "Interviewing Methods in the Health Interview Survey" which is on the Internet at: http://www.cdc.gov/nchs/data/series/sr_02/sr02_048.pdf This questionnaire was used during the July-December 1967 period. Page 72 of "Interviewing Methods in the Health Interview Survey" has Cards A, B, D, E, F, G, H, and I. Appendix III of "Interviewing Methods in the Health Interview Survey" provides the fiscal year 1967 condition approach questionnaire, which is essentially identical to the fiscal year 1968 condition approach questionnaire. Two other NHIS questionnaires used during the July 1967-June 1968 period (fiscal year 1968 condition approach questionnaire, person approach questionnaire dated 12-1-67, used January-June 1968) and other materials are available at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Survey_Questionnaires/NHIS/1968/ File File Name Description of Component Format Q_PERSON_APPROACH_1967_12_01.PDF Adobe PDF Person approach questionnaire dated 12-1-67 Q_CONDITION_APPROACH_1966_09_30.PDF Adobe PDF Fiscal year 1968 condition approach questionnaire MVPACDNT_SUPPLEMENT_1967_06_01.PDF Adobe PDF Motor Vehicle Accident supplement dated 6-1-67 HOSPITAL_SUPPLEMENT_1967_12_11.PDF Adobe PDF Hospital supplement dated 12-11-67 DOCTOR_SURGEON_BILL_SUPPLEMENT_1967_07_11.PDF Adobe PDF Doctor's and Surgeon's Bill supplement dated 7-11-67 DOCTOR_SURGEON_BILL_SUPPLEMENT_1967_12.PDF Adobe PDF Doctor's and Surgeon's Bill supplement dated 12-67 CARD_C.PDF Card C Adobe 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 1968 were collected for 52 weeks. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *