National 2009 H1N1 Flu Survey (NHFS) Public-Use Data File (PUF) 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 ensure 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 (1 (800) 232-4636). 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 requirements. INTRODUCTION The National 2009 H1N1 Flu Survey (NHFS) was sponsored by the National Center for Immunization and Respiratory Diseases (NCIRD) and conducted jointly by NCIRD and the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC). The NHFS was a list-assisted random-digit-dialing telephone survey of households, designed to monitor influenza immunization coverage in the 2009-10 season. The target population for the NHFS was all persons 6 months or older living in the United States at the time of the interview. Data from the NHFS were used to produce timely estimates of vaccination coverage rates for both the monovalent pH1N1 and trivalent seasonal influenza vaccines. For more information, see: http://www.cdc.gov/nchs/nis/about_nis.htm#h1n1 CONTENTS OF THE NHFS PUF The overall package consists of seven computer files, as follows: --------------------------------------------------------------------------------- NAME.TYPE File Description Size (KB) --------------------------------------------------------------------------------- NHFSPUF_README.TXT 8 Readme File (this text) NHFSPUF_DUG.PDF 1,069 NHFS PUF Data User's Guide (Adobe Acrobat format) NHFSPUF_CODEBOOK.PDF 620 NHFS PUF Data Documentation, Codebook, and Frequencies (Adobe Acrobat format) NHFSPUF.DAT 17,459 NHFS PUF Dataset (ASCII format) NHFSPUF.SAS 32 SAS Input Statements (ASCII format, SAS v 9.2) NHFSPUF.R 47 R Input Statements (ASCII format, R v 2.8.1) NHFSPUF_QUEX.PDF 444 NHFS Questionnaire (Adobe Acrobat format) --------------------------------------------------------------------------------- The NHFS public-use data file is available in ASCII format. The actual file is in a compressed format and can be expanded using WinZip or other software. A SAS program (in ASCII format) is provided to facilitate reading the ASCII data file and creating a SAS dataset. The SAS program contains, for each variable in the ASCII file, the variable name, its starting position and width, labels, and formats. AN R program (in ASCII format) is also provided to facilitate reading the ASCII data file and creating a R dataset. The R program contains, for each variable in the ASCII file, the variable name, its starting position and width, labels, and formats. The data file NHFSPUF.DAT can be used for processing by statistical software packages that accept ASCII-formatted input, or it can be transferred to another computer for processing. For more information about the NHFS PUF, data users should consult the NHFS PUF Data User's Guide and the NHFS PUF Data Documentation, Codebook, and Frequencies. Users of these data must review that descriptive and explanatory documentation to analyze the data correctly. These documents are available in PDF format. The NHFS PUF Data User's Guide provides detailed information about the design of the NHFS sample, the questionnaire, the weighting and estimation procedures, and other important information needed for analyzing these data. The NHFS PUF Data Documentation, Codebook and Frequencies contains indexes of the variables (in both section order and alphabetical order), the variable responses, and either unweighted frequencies of categorical variables or unweighted summary statistics for continuous variables. The NHFS files are large. Please use caution and check the capacity of your disk drive before downloading them. Documents in PDF format can be viewed with Adobe Acrobat software. The Adobe Acrobat Reader can be downloaded from the Adobe Acrobat website at: http://www.adobe.com/products/acrobat/readstep2.html UNIQUE IDENTIFIERS AND WEIGHTING The unique household identification number is SEQNUMHH. The unique person-level identification number is SEQNUMP. SEQNUMP consists of 6 digits: the first five digits are SEQNUMHH and the sixth digit uniquely identifies the person within the household. The sampling weight is called FLUWT. GUIDELINES FOR CITATION OF DATA With the goal of mutual benefit, the National Center for Health Statistics (NCHS) and the National Center for Immunization and Respiratory Diseases (NCIRD) request that recipients of data files cooperate in certain actions related to their use. Any published material derived from these data should acknowledge CDC (NCHS and NCIRD) as the original data source and use "NHFS" in the title or as a keyword in the abstract. The suggested citation to appear at the bottom of all tables is as follows: Source: CDC, NCRID and NCHS (2012), National 2009 H1N1 Flu Survey. The reference for the NHFS data file is: U.S. Department of Health and Human Services (DHHS). National Center for Health Statistics. The National 2009 H1N1 Flu Survey. Hyattsville, MD: Centers for Disease Control and Prevention, 2012. Published material should also include a disclaimer that attributes 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 ensure that the description is consistent with that published by NCHS. Although the data files have been edited carefully, errors may be detected. Please notify NCHS staff (1 (800) 232-4636) of any errors in the NHFS data or documentation. For additional information on the NHFS public-use data file, please contact the NCHS Information Dissemination staff: Information Dissemination Staff, NCHS 3311 Toledo Road Hyattsville, MD 20782 Phone: 1 (800) 232-4636 Email: cdcinfo@cdc.gov Internet: http://www.cdc.gov/nchs/