2002 NATIONAL HEALTH INTERVIEW SURVEY (NHIS) November 3, 2004 PUBLIC USE DATA RELEASE * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * WARNING - DATA USE RESTRICTIONS! Read Carefully Before Use 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 (NCHS), 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. SURVEY DESCRIPTION DOCUMENT Please see the Survey Description Document for even more documentation about the 2002 NHIS. For the location of the Survey Description Document, please see the section below entitled "2002 NHIS DOCUMENTATION FILES". 2002 NHIS STRUCTURE The NHIS contains many similar questions every year. The repeated items are called "core questions". Beginning with a new NHIS design in 1997, these core questions were divided into three components -- Family, Sample Adult, and Sample Child. In some years, the NHIS also has supplemental questions/modules. The 2002 NHIS contains the core questions along with questions on Disability and also on Alternative Health / Complementary and Alternative Medicine. All of these additional 2002 questions were asked of Sample Adults. The results of the Disability questions can be found in the Sample Adult output file. The results of the Alternative Health questions can be found in two separate Alternative Health output files. The 2002 NHIS files consist of six questionnaires and ten data files. See the Survey Description document for more details. The following chart shows the output data files for the 2002 NHIS components: Component Questionnaire Output Data File ----------------- ------------- ---------------------- Family Core Household Household " Family Family " " Person " " Injury/Poison Episode " " Injury/Poison Verbatim Sample Adult Core Sample Adult Sample Adult Disability Module " " Alt. Health Module " Alternative Health " " Altern. Health Verbatim Sample Child Core Sample Child Sample Child " Immunization Immunization -- Recontact -- 2002 NHIS FILES AND DOCUMENTATION The various files listed below comprise the 2002 National Health Interview Survey (NHIS) public use data release. A copy of this file (README.TXT), in ASCII format, is located with each of the following file groups (survey questionnaires, data files, SAS/ SPSS/STATA input statements, and documentation). 2002 NHIS SURVEY QUESTIONNAIRES, ETC. The 2002 NHIS is broken into six questionnaires - Household, Family, Sample Adult, Sample Child, Immunization, and Recontact. The questionnaires that are provided with the release of the 2002 NHIS are not identical to the versions that were utilized in the field. The questionnaires provided here reflect the minor changes in data presentation that occurred during the editing process. 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). Also included is a flowchart that shows how a respondent would move through the various questionnaires. The survey questionnaires, flashcards, and Field Representative Manual 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 Format (KB) (Pages) QHOUSHLD.PDF Household Questionnaire PDF 105 17 QFAMILYX.PDF Family Core Questionnaire PDF 499 86 QSAMADLT.PDF Sample Adult Core Questionnaire PDF 477 94 QSAMCHLD.PDF Sample Child Core Questionnaire PDF 123 20 QIMMUNIZ.PDF Immunization Questionnaire PDF 166 20 QRECONCT.PDF Recontact Questionnaire PDF 48 6 FLASHCRD.PDF Flashcards PDF 5,527 178 FRMANUAL.PDF FR Manual PDF 1,551 334 NHISFLOW.PDF NHIS System Flow Chart PDF 15 1 The survey questionnaires, flashcards, flow chart, and Field Representative Manual are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Survey_Questionnaire s/NHIS/2002 2002 NHIS DATA FILES The 2002 NHIS has been divided into ten data files. For ease of transmission, each of the 2002 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 NHIS2002. To do this, create a directory on your C: drive called NHIS2002. Then, using your browser, go to the FTP site containing the 2002 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:\nhis2002\HOUSEHLD.EXE in the box labeled File Name and hit Enter. To then convert HOUSEHLD.EXE into the ASCII file HOUSEHLD.DAT, go to the directory NHIS2002 and do the following: - From DOS - in the c:\nhis2002 directory, type HOUSEHLD and hit Enter - From Windows - Double-click on HOUSEHLD.EXE or Click the Start Button, Click Run, enter c:\nhis2002\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 2002 NHIS files are large in size. Please use caution and check your disk drive capacity before extracting. NOTE: Users have encountered difficulties when downloading the data files onto their 'Desktop'. When downloading the data files, please use a separate folder (directory). ------ File Size ----- File Compressed Original File Name Description Format (KB) (KB) ALTHEALT.EXE Alternative Health Data ASCII 1,035 52,690 ALTVERBT.EXE Altern. Health Verbatim ASCII 251 39,351 FAMILYXX.EXE Family Data ASCII 1,093 6.942 HOUSEHLD.EXE Household Data ASCII 408 2,366 IMMUNIZE.EXE Immunization Data ASCII 588 8.973 INJPOIEP.EXE Injury/Poison Episode ASCII 47 280 INJVERBT.EXE Injury/Poison Verbatim ASCII 90 1,253 PERSONSX.EXE Person Data ASCII 4,443 69,675 SAMADULT.EXE Sample Adult Data ASCII 3,300 27,194 SAMCHILD.EXE Sample Child Data ASCII 522 2,997 The 2002 NHIS data files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS/2002 2002 NHIS SAS, SPSS AND STATA INPUT STATEMENTS Sample SAS, SPSS, and STATA input statement programs have been provided for each data file. By using the ASCII data files (.DAT files) as input to these programs, SAS, SPSS, or STATA data files can be created. The SAS, SPSS, and STATA input statement programs are stored in ASCII format. STATA programs have not been provided prior to this data year. File File Size File Name Description Format (KB) ALTHEALT.SAS Alternative Health SAS program ASCII 191 ALTVERBT.SAS Alt. Health Verbatim SAS program ASCII 4 FAMILYXX.SAS Family SAS program ASCII 21 HOUSEHLD.SAS Household SAS program ASCII 9 IMMUNIZE.SAS Immunization SAS program ASCII 50 INJPOIEP.SAS Injury/Poison Episode SAS program ASCII 25 INJVERBT.SAS Injury/Poison Verbatim SAS program ASCII 5 PERSONSX.SAS Person SAS program ASCII 100 SAMADULT.SAS Sample Adult SAS program ASCII 120 SAMCHILD.SAS Sample Child SAS program ASCII 43 ALTHEALT.SPS Alternative Health SPSS programs ASCII 364 ALTVERBT.SPS Alt. Health Verbatim SPSS program ASCII 2 FAMILYXX.SPS Family SPSS program ASCII 18 HOUSEHLD.SPS Household SPSS program ASCII 6 IMMUNIZE.SPS Immunization SPSS program ASCII 84 INJPOIEP.SPS Injury/Poison Episode SPSS program ASCII 24 INJVERBT.SPS Injury/Poison Verbatim SPSS pgm ASCII 3 PERSONSX.SPS Person SPSS program ASCII 145 SAMADULT.SPS Sample Adult SPSS program ASCII 169 SAMCHILD.SPS Sample Child SPSS program ASCII 44 ALTHEALT.DO Alternative Health STATA programs ASCII 166 ALTVERBT.DO Alt. Health Verbatim STATA program ASCII 2 FAMILYXX.DO Family STATA program ASCII 19 HOUSEHLD.DO Household STATA program ASCII 7 IMMUNIZE.DO Immunization STATA program ASCII 42 INJPOIEP.DO Injury/Poison Episode STATA program ASCII 23 INJVERBT.DO Injury/Poison Verbatim STATA pgm ASCII 4 PERSONSX.DO Person STATA program ASCII 96 SAMADULT.DO Sample Adult STATA program ASCII 117 SAMCHILD.DO Sample Child STATA program ASCII 40 The 2002 NHIS sample SAS, SPSS, and STATA input statement programs are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/20 02 2002 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 2002 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 Format (KB) (Pages) ALTHEALT.PDF Alternative Health File Layout PDF 2,558 456 ALTVERBT.PDF Alt Hlth. Verbatim File Layout PDF 59 13 FAMILYXX.PDF Family File Layout PDF 410 92 HOUSEHLD.PDF Household File Layout PDF 77 15 IMMUNIZE.PDF Immunization File Layout PDF 620 110 INJPOIEP.PDF Inj/Poi Episode File Layout PDF 411 82 INJVERBT.PDF Inj/Poi Verbatim File Layout PDF 43 9 PERSONSX.PDF Person File Layout PDF 2,587 454 SAMADULT.PDF Sample Adult File Layout PDF 3,590 526 SAMCHILD.PDF Sample Child File Layout PDF 843 140 SRVYDESC.PDF Survey Description Document PDF 578 98 The 2002 NHIS documentation files are located at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentatio n/NHIS/2002 2002 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, Alternative Health, and Alternative Health Verbatim) have been sorted by the Person Number (PX) within the Household Serial Number (HHX). The injury files (Injury/Poison Episode and Injury/Poison Verbatim) have been sorted by Person Number (PX) and Injury/Poison Episode Number (IPEPNO) within the Household Serial Number (HHX). MERGING 2002 NHIS DATA FILES To merge data from the Household file into the Family file, or into any of the person-level files (Person, Sample Adult, Sample Child, Immunization, Alternative Health, or Alternative Health Verbatim) or into any of the episode-level files (Injury/Poison Episode and Injury/Poison Verbatim), 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 IPEPNO. 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 NHIS data products: Phone : 301-458-4901 FAX : 301-458-4035 E-mail : nhislist@cdc.gov. Internet: http://www.cdc.gov/nchs/nhis.htm For additional information on other NCHS data products: Phone : 301-458-INFO [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.