!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 dataset. 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 this dataset 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. 3. Not link this dataset with individually identifiable data from other NCHS or non-NCHS datasets. ************************************************** BY USING THESE DATA, YOU SIGNIFY YOUR AGREEMENT TO COMPLY WITH THE ABOVE-STATED STATUTORILY-BASED AGREEMENTS. ************************************************** This CD-ROM contains the 1979-2007 National Hospital Discharge Survey Multi-Year Datafiles. Four separate files, all in ASCII format, are included, one containing records for newborn infants, only, for all years from 1979 through 2007, and three files separating records for non-newborns in to those for the 1979 through 1989 data years,1990 through 1999 data years and 2000 through 2007 data years. The data file documentation is provided in Adobe Acrobat PDF format. NOTE: You will need Adobe Acrobat Reader software to view this file. The Reader software can be downloaded for free from: http://www.adobe.com/products/acrobat/readstep2.html. Also provided in PDF format are the ICD-9-CM Addenda from 1986-2006 which are summarized in the Conversion Table, as well as two medical abstract forms (HDS-1), one used for data abstraction in 2001, and the other in 2007. To accompany Appendices B and E of the documentation, there are several EXCEL files, which contain information needed to calculate relative standard errors (RSEs) of NHDS statistics and to compute utilization rates based on Census population estimates. According to their contents, these files reside in directories named either RSES or POPS. -------------------------------------------------------------------------------- CAUTION - BECAUSE THE NHDS IS A SAMPLE SURVEY, THE APPLICATION OF WEIGHTS TO THE SAMPLE DATA IS NECESSARY IN ORDER TO PRODUCE NATIONAL ESTIMATES OF INPATIENT HOSPITAL UTILIZATION. -------------------------------------------------------------------------------- The following is a list of files contained on this CD: "NHDS7907.NEWBORN.TXT" NHDS 1979-2007 ASCII dataset containing records for newborn infants only, for the 1979 through 2007 data years "NHDS7989.NOTNB.TXT" NHDS 1979-1989 ASCII dataset containing non-newborn records for the 1979 through 1989 data years only "NHDS9099.NOTNB.TXT" NHDS 1990-1999 ASCII dataset containing non-newborn records for the 1990 through 1999 data years only "NHDS0007.NOTNB.TXT" NHDS 2000-2007 ASCII dataset containing non-newborn records for the 2000 through 2007 data years only "NHDS MultiYear Datafile Documentation, 1979-2007.pdf" NHDS 1979-2007 data file documentation in Adobe Acrobat PDF format "MedicalAbstract_2001.pdf" HDS-1 form used for abstracting medical and demographic data of sampled inpatients in 2001 (revised to include two new variables) "MedicalAbstract_2007.pdf" HDS-1 form used for abstracting medical and demographic data of sampled inpatients in 2007. "ICD-9-CM Addenda for 1986-2006.pdf" This is a PDF document listing diagnosis and procedure code changes and the year they took effect, between 1986 and 2006. "SAS_INPUT_1979-2007.txt" This is a SAS program to input the data file and create a working SAS dataset. This program is in ASCII format and can be copied or transferred to the operating system used to process the data. "/RSES" is a directory containing EXCEL spreadsheets of tables that include information needed to calculate relative standard errors (RSEs) of NHDS estimates. These EXCEL files have parameter values for RSE curves for 1979 through 2007. Files are designated as XXXXRSE.xls, where XXXX is replaced by a data year between 1979 and 2007 (e.g. 1979). Refer to Appendix B in the data file documentation for instructions on how to perform RSE calculations. "/POPS" is a directory containing EXCEL spreadsheets of tables that include population estimates needed to calculate hospital utilization rates by age, sex, and race or geographic region. These EXCEL files have U.S. Census population estimates for 1979 through 2007. Files are designated as XXXXRACE.xls or XXXXREG.xls, where xxxx can be replaced by a data year between 1979 and 2007. The xxxxRACE files contain population estimates for single-year ages by sex and race. The xxxxREG files contain population estimates for single-year ages by sex and geographic region. See Appendix E for a complete list of these files and a more detailed explanation of their contents. ----------------------------------------------------------------------- For questions concerning NHDS data, please contact: Centers for Disease Control and Prevention National Center for Health Statistics Division of Health Care Statistics Ambulatory and Hospital Care Statistics Branch 3311 Toledo Road Hyattsville, Maryland 20782 Phone: 301.458.4321 Fax: 301.458.4032 Email: NHDS@cdc.gov For more information about the NHDS, visit the NCHS website: http://www.cdc.gov/nchs/nhds.htm For email discussions and dissemination of NHDS data, join the Hospital Discharge and Ambulatory Surgery Data listserv (HDAS-DATA). To join the listserv, in the body of an email message (leaving the subject line blank), type: subscribe hdas-data Your Name Then send this message to: listserv@cdc.gov For additional information on NCHS data products, please contact: National Center for Health Statistics Data Dissemination Branch 3311 Toledo Road Hyattsville, Maryland 20782 Tel: (301) 458-INFO E-mail: nchsquery@cdc.gov Internet: http://www.cdc.gov/nchs/