NATIONAL HEALTH INTERVIEW SURVEY (NHIS) Public-use Linked Mortality Files SURVEY YEARS 1986-2004 Updated December 11, 2013 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 either omitted from the data files or perturbed to prevent re-identification. 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 NCHS conducted an updated linkage of the National Health Interview Survey (NHIS) to death certificate data found in the National Death Index (NDI). Linkage of the NHIS survey participants with the NDI provides the opportunity to conduct studies designed to investigate the association of a variety of health factors with mortality, using the richness of the NHIS questionnaires. NCHS recommends that researchers use these new linked mortality files as they supersede all prior data releases of the NHIS Public-use Linked Mortality files. NCHS used a different linkage methodology for this NHIS-NDI linkage than previous NHIS-NDI linkages. DATA FILE DESCRIPTION The NHIS Public-use Linked Mortality Files include the NHIS survey years 1986 to 2004 with mortality follow-up through December 31, 2006. Mortality information is based upon the results from a probabilistic match between NHIS and NDI death certificate records. All NHIS participants are included on the Public-use Linked Mortality Files. Each NHIS survey year (1986-2004) is available on a separate data file, with a consistent file format for all years. MORTALITY LINKAGE METHODOLOGY DOCUMENTATION NCHS employed a matching methodology for the NHIS Linked Mortality Files that was similar, but not identical, to the standard methodology offered by the NDI. The matching methodology document contains detailed information regarding the methodology utilized for the linkage. Users are urged to carefully read this document to gain a better understanding of the matching methodology employed to link NHIS records to death records in the NDI. The matching methodology document can be found at this web site: http://www.cdc.gov/nchs/data/datalinkage/matching_methodology_nhis_final_2010.pdf NHIS PUBLIC-USE LINKED MORTALITY FILE SAMPLE PROGRAMS There are two sample programs provided to assist researchers when reading in the NHIS Public-use Linked Mortality ASCII files. The first sample program provides data input statements. By using the ASCII data file (.DAT file) as input to the program, other types of data files (e.g. SAS, SPSS) can be created. The NHIS sample ASCII input statement program that reads in the NHIS 1990 Public-use Linked Mortality File can be found at this web site: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/datalinkage/linked_mortality/nhis_sample_ascii_pgm_2010.sas The second sample program provides researchers using STATA with code to read in the data file and run their analyses using the STATA software. The NHIS sample STATA program that readS in the NHIS 1990 Public-use Linked Mortality File can be found at this web site: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/datalinkage/linked_mortality/nhis_sample_stata_ascii_pgm_2010.do NOTE TO STATA USERS: If STATA users click on the "Sample STATA Program" link, STATA may attempt to automatically run the program, resulting in an error message. To avoid getting an error message, we suggest STATA users save the program by right clicking on the link "Sample STATA Program" and select the "Save Target As" option. FILE NAME FILE DESCRIPTION FORMAT (KB) NHIS86_MORT_PUBLIC_USE.ASCII NHIS 1986 Linked Mortality File ASCII NHIS87_MORT_PUBLIC_USE.ASCII NHIS 1987 Linked Mortality File ASCII NHIS88_MORT_PUBLIC_USE.ASCII NHIS 1988 Linked Mortality File ASCII NHIS89_MORT_PUBLIC_USE.ASCII NHIS 1989 Linked Mortality File ASCII NHIS90_MORT_PUBLIC_USE.ASCII NHIS 1990 Linked Mortality File ASCII NHIS91_MORT_PUBLIC_USE.ASCII NHIS 1991 Linked Mortality File ASCII NHIS92_MORT_PUBLIC_USE.ASCII NHIS 1992 Linked Mortality File ASCII *nhis92_mod_mort_public_use.ASCII NHIS 1992 Modified Linked Mortality File ASCII NHIS93_MORT_PUBLIC_USE.ASCII NHIS 1993 Linked Mortality File ASCII NHIS94_MORT_PUBLIC_USE.ASCII NHIS 1994 Linked Mortality File ASCII NHIS95_MORT_PUBLIC_USE.ASCII NHIS 1995 Linked Mortality File ASCII NHIS96_MORT_PUBLIC_USE.ASCII NHIS 1996 Linked Mortality File ASCII NHIS97_MORT_PUBLIC_USE.ASCII NHIS 1997 Linked Mortality File ASCII NHIS98_MORT_PUBLIC_USE.ASCII NHIS 1998 Linked Mortality File ASCII NHIS99_MORT_PUBLIC_USE.ASCII NHIS 1999 Linked Mortality File ASCII NHIS00_MORT_PUBLIC_USE.ASCII NHIS 2000 Linked Mortality File ASCII NHIS01_MORT_PUBLIC_USE.ASCII NHIS 2001 Linked Mortality File ASCII NHIS02_MORT_PUBLIC_USE.ASCII NHIS 2002 Linked Mortality File ASCII NHIS03_MORT_PUBLIC_USE.ASCII NHIS 2003 Linked Mortality File ASCII NHIS04_MORT_PUBLIC_USE.ASCII NHIS 2004 Linked Mortality File ASCII *In 1992, the NHIS included an oversample of Hispanics by re-interviewing the 1991 households that were identified as containing people of Hispanic heritage. Records for the oversample of Hispanic persons (those also sampled in 1991) have been deleted from the NHIS 1992 Modified Linked Mortality File and the weights of the remaining sample have been revised accordingly. These are the only changes to these files. These revised files have been created primarily for those who need to combine 1991 and 1992 data files for analytic purposes. NHIS PUBLIC-USE LINKED MORTALITY FILE DOCUMENTATION There is a data file layout (also called data dictionary) associated with the NHIS Public-use Linked Mortality Data Files. The data file layout is the same for NHIS 1986-2004 and is in PDF format that 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 The data file layout can be found at this web site: http://www.cdc.gov/nchs/data/datalinkage/nhis_file_layout_public_2010.pdf NHIS PUBLIC-USE LINKED MORTALITY FILES' RECORD SEQUENCE All records on the NHIS Public-use Linked Mortality Files have been sorted by the NHIS person level PUBLICID. Detailed instructions are provided showing the construction of the NHIS PUBLICID at this web site: http://www.cdc.gov/nchs/data/datalinkage/nhis_file_layout_public_2010.pdf MERGING THE NHIS PUBLIC-USE LINKED MORTALITY FILES TO OTHER PUBLIC-USE NHIS FILES To merge data from the NHIS Public-use Linked Mortality Files to the person level public-use NHIS files, the PUBLICID variable provided on the Linked Mortality Files should be used. User should review the Detailed Notes for Selected Variables in the file layout to construct the PUBLICID at the web site: http://www.cdc.gov/nchs/data/datalinkage/nhis_file_layout_public_2010.pdf For users who prefer to include the NHIS family serial number in the NHIS public-use Id number, an additional public-use Id, PUBLICID_2, has been included on the Public-use NHIS Linked Mortality Files. PUBLICID_2 is only available on the NHIS 1997-2003 Linked Mortality Files. Refer to the detailed notes for the creation of the NHIS public-use Id number, PUBLICID, for NHIS survey years 1986-1996. Both PUBLICID and PUBLICID_2 provide unique person-level Id numbers. http://www.cdc.gov/nchs/data/datalinkage/nhis_file_layout_public_2010.pdf Users who want to combine across multiple NHIS survey years, should: 1. Review the NHIS 1992 readme file (link below) regarding use of the modified 1992 NHIS public-use files to remove the Hispanic oversample when combining the NHIS years 1991 and 1992. ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Program_Code/NHIS/1992/readmenh.txt 2. Use the new eligibility-adjusted sample weights. Users should refer to the Analytic Guidelines document for notes on the variables WGT_NEW and SA_WGT_NEW at the web site: http://www.cdc.gov/nchs/data/datalinkage/nhis_mort_analytic_guidelines.pdf 3. Refer to the detailed notes in the file layout on the public-use ID construction when merging the NHIS 1986-2004 public-use survey files to the NHIS 1986-2004 Public-use Linked Mortality Files at the web site: http://www.cdc.gov/nchs/data/datalinkage/nhis_file_layout_public_2010.pdf CONTACT INFORMATION Updates about new data releases, publications, or errors will be sent to members of the NHIS Listserv. To join, visit the website at: http://www.cdc.gov/nchs/about/major/nhis/nhislist.htm For additional information on NHIS data linkage products, please visit the NCHS data linkage web page at: http://www.cdc.gov/nchs/data_access/data_linkage_activities.htm 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 : 800-CDC-INFO E-mail : nchsquery@cdc.gov Internet: http://www.cdc.gov/nchs Although the NHIS Public-use Linked Mortality Files were carefully edited, errors may be detected. Please e-mail the NCHS Data Linkage Staff at datalinkage@cdc.gov if any errors are detected in the NHIS Public-use Linked Mortality File(s) data or documentation. 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. GUIDELINES FOR CITATION OF THE 1986-2004 NHIS PUBLIC-USE LINKED MORTALITY DATA With the goal of mutual benefit, the National Center for Health Statistics (NCHS) requests that recipients of data files cooperate in certain actions related to their use. Any published material derived from the data should acknowledge NCHS as the original source. The suggested citation to appear at the bottom of all published tables is as follows: Source: National Center for Health Statistics When cited in a bibliography, the citation should read: National Center for Health Statistics. Office of Analysis and Epidemiology, Public-use National Health Interview Survey Linked Mortality Files, 2010. Hyattsville, Maryland. (Available at the following address: http://www.cdc.gov/nchs/data_access/data_linkage/mortality/nhis_linkage.htm) The published material should also include a disclaimer that credits any analyses, interpretations, or conclusions reached to the author (recipient of the data file) and not to NCHS, which is responsible only for the initial data. Consumers who wish to publish a technical description of the data should make an effort to insure that the description is not inconsistent with that published by NCHS.