1998 NATIONAL HEALTH INTERVIEW SURVEY 04/05/2001 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 (301-458-4500). 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 noninstitutionalized 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. NOTE TO USERS The 1997 and 1998 NHIS changed significantly in virtually all aspects of questionnaire design and content compared to 1996 and prior years. As with any newly designed system, there may be occasions when corrections or updates are found to be necessary. 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. 1998 NHIS FILES AND DOCUMENTATION The files listed below comprise the 1998 National Health Interview Survey (NHIS) final public use data release. A copy of this file (README.TXT), in ASCII format, is located within each of the following file groups. 1998 NHIS DATA FILES The 1998 NHIS data have been divided into 12 data files. For ease of transmission, each of the 1998 NHIS data files have 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 NHIS1998. To do this, create a directory on your C: drive called NHIS1998. Then, using your browser, go to the FTP site containing the 1998 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:\nhis1998\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 NHIS1998 and do the following: - From DOS - in the c:\nhis1998 directory, type HOUSEHLD and hit Enter - From Windows - Double-click on HOUSEHLD.EXE or Click the Start Button, Click Run, enter c:\nhis1998\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 1998 NHIS files are large in size. Please use caution and check your disk drive capacity before extracting. ------- File Size ------ Description File Compressed Uncompressed File Name of Component Format (KB) (KB) HOUSEHLD.EXE Household Data ASCII 325 2,529 FAMILYXX.EXE Family Data ASCII 1,056 7,005 PERSONSX.EXE Person Data ASCII 4,371 74,861 SAMADULT.EXE Sample Adult Data ASCII 2,405 24,235 SAMCHILD.EXE Sample Child Data ASCII 512 2,759 IMMUNIZE.EXE Immunization Data ASCII 617 9,480 INJEPSOD.EXE Injury Episode " ASCII 61 400 INJVERBT.EXE Injury Verbatim " ASCII 134 1,821 POIEPSOD.EXE Poison Episode " ASCII 6 8 PREGSMKG.EXE Preg.& Smoking " ASCII 351 1,863 PREVADLT.EXE Prevent. Adult " ASCII 2,116 15,420 PREVCHLD.EXE Prevent. Child " ASCII 352 1,893 The 1998 NHIS data files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS/1998 1998 NHIS SAS AND SPSS INPUT STATEMENTS Sample SAS and SPSS input statement programs have been provided for each data file. By using the ASCII data files (.DAT files) as input to these programs, SAS and SPSS data files can be created. The SAS and SPSS input statement programs are stored in ASCII format. File File Size File Name Description of Component Format (KB) HOUSEHLD.SAS Household SAS program ASCII 9 FAMILYXX.SAS Family SAS program ASCII 21 PERSONSX.SAS Person SAS program ASCII 98 SAMADULT.SAS Sample Adult SAS program ASCII 94 SAMCHILD.SAS Sample Child SAS program ASCII 34 IMMUNIZE.SAS Immunization SAS program ASCII 43 INJEPSOD.SAS Injury Episode SAS program ASCII 24 INJVERBT.SAS Injury Verbatim SAS program ASCII 3 POIEPSOD.SAS Poison Episode SAS program ASCII 7 PREGSMKG.SAS Preg.& Smoking SAS program ASCII 14 PREVADLT.SAS Prevention Adult SAS program ASCII 73 PREVCHLD.SAS Prevention Child SAS program ASCII 25 HOUSEHLD.SPS Household SPSS program ASCII 6 FAMILYXX.SPS Family SPSS program ASCII 17 PERSONSX.SPS Person SPSS program ASCII 147 SAMADULT.SPS Sample Adult SPSS program ASCII 136 SAMCHILD.SPS Sample Child SPSS program ASCII 36 IMMUNIZE.SPS Immunization SPSS program ASCII 81 INJEPSOD.SPS Injury Episode SPSS program ASCII 24 INJVERBT.SPS Injury Verbatim SPSS program ASCII 2 POIEPSOD.SPS Poison Episode SPSS program ASCII 5 PREGSMKG.SPS Preg.& Smoking SPSS program ASCII 10 PREVADLT.SPS Prevention Adult SPSS program ASCII 87 PREVCHLD.SPS Prevention Child SPSS program ASCII 25 The 1998 NHIS sample SAS and SPSS input statement programs are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1998 1998 NHIS DOCUMENTATION FILES There is a data file layout (also called data dictionary) associated with each data file. There is also a Survey Description document which contains general information about the 1998 NHIS. The documentation files 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/prodindex/acrobat/readstep.html File --File Size-- File Name Description of Component Format (KB) (Pages) HOUSEHLD.PDF Household File Layout PDF 18 16 FAMILYXX.PDF Family File Layout PDF 58 62 PERSONSX.PDF Person File Layout PDF 487 497 SAMADULT.PDF Sample Adult File Layout PDF 463 453 SAMCHILD.PDF Sample Child File Layout PDF 125 111 IMMUNIZE.PDF Immunization File Layout PDF 93 88 INJEPSOD.PDF Injury Episode File Layout PDF 82 82 INJVERBT.PDF Injury Verbatim File Layout PDF 10 9 POIEPSOD.PDF Poison Episode File Layout PDF 15 13 PREGSMKG.PDF Preg.& Smoking File Layout PDF 36 35 PREVADLT.PDF Prevention Adult File Layout PDF 321 308 PREVCHLD.PDF Prevention Child File Layout PDF 72 72 SRVYDESC.PDF Survey Description Document PDF 178 76 The 1998 NHIS data file layout documentation files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentatio n/NHIS/1998 1998 NHIS SURVEY QUESTIONNAIRES, ETC. The 1998 NHIS contains the annual Basic Module which is broken into six questionnaire components - Household, Family Core, Sample Adult Core, Sample Child Core, Immunization, and Recontact; the 1998 NHIS also includes the Prevention Module which is broken into three questionnaire components - Prevention Adult, Prevention Child, and Pregnancy and Smoking. The flashcards were handed to the respondents to facilitate their ability to answer certain questions - these are referenced in the questionnaires. The Field Representative Manual contains the guidelines and instructions on the survey process and topic areas covered by the NHIS and was provided to the Field Representatives (also known as interviewers). The survey questionnaires, flashcards, and Field Representative Manual are in PDF format. Also included is a flowchart that shows how a respondent would move through the various questionnaire components. File --File Size-- File Name Description of Component Format (KB) (Pages) QHOUSHLD.PDF Household Questionnaire PDF 27 12 QFAMILYX.PDF Family Core Questionnaire PDF 104 56 QSAMADLT.PDF Sample Adult Core Questionnaire PDF 59 34 QSAMCHLD.PDF Sample Child Core Questionnaire PDF 34 17 QIMMUNIZ.PDF Immunization Questionnaire PDF 37 17 QPREGSMG.PDF Preg.& Smoking Questionnaire PDF 12 4 QPREVSAD.PDF Prevention Adult Questionnaire PDF 74 45 QPREVSCH.PDF Prevention Child Questionnaire PDF 19 9 QRECONCT.PDF Recontact Questionnaire PDF 14 5 FLASHCRD.PDF Flashcards PDF 755 70 Field Representative (FR) Manual (in four parts) FRMANU_A.PDF Part A - FR Manual PDF 208 24 FRMANU_B.PDF Part B - FR Manual PDF 191 53 FRMANU_C.PDF Part C - FR Manual PDF 448 213 FRMANU_D.PDF Part D - FR Manual PDF 296 150 NHISFLOW.PDF Questionnaire Flowchart PDF 8 1 The survey questionnaires, flashcards, and Field Representative Manual are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Survey_Questionnair es/NHIS/1998 1998 NHIS DATA FILES' RECORD SEQUENCE All records in the NHIS data files have first been sorted by the Household Serial Number (HHX). The Family file has been sorted by the Family Serial Number (FMX) within the Household Serial Number (HHX). The person-level files (Person, Sample Adult, Sample Child, Immunization, Pregnancy and Smoking, Prevention Sample Adult, and Prevention Sample Child) have been sorted by the Person Number (PX) within the Household Serial Number (HHX). The injury files (Injury Episode and Injury Verbatim) have been sorted by Person Number (PX) and Injury Episode Number (INJEPNO) within the Household Serial Number (HHX). The Poison Episode file has been sorted by Person Number (PX) and Poison Episode Number (POIEPNO) within the Household Serial Number (HHX). MERGING 1998 NHIS DATA FILES To merge data from the Household file into the Family file, into any of the person-level files (Person, Sample Adult, Sample Child, Immunization, Pregnancy and Smoking, Prevention Sample Adult, and Prevention Sample Child) or into any of the episode-level files (Injury Episode, Injury Verbatim, and Poison Episode), merge by variable HHX. To merge any person-level file with another person-level file or with an episode-level file, merge by variables HHX and PX. To merge one Injury file with the other Injury file, merge by variables HHX, PX, and INJEPNO. To merge the Family file information into a person-level or episode-level file, re-sort the person-level or episode-level file by variables HHX and FMX and then merge by HHX and FMX. 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/subscribe.html Input your name and E-mail address, select the item "National Health Interview Survey (NHIS) researchers", and click the "Subscribe" button. For additional information on the NHIS, visit the website at: http://www.cdc.gov/nchs/nhis.htm For assistance with the 1998 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 6525 Belcrest 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.