1999 National Hospital Ambulatory Medical Care Survey Data File and File Documentation 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 requirements. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Please continue to next page. - 1 - The files listed below comprise the 1999 National Hospital Ambulatory Medical Care Survey with complete file documentation. The 1999 NHAMCS dataset includes two files, one for emergency department data and another for outpatient department data. These are located in: /public/pub/Health_Statistics/NCHS/Datasets/NHAMCS The documentation file for the 1999 NHAMCS dataset is located in: /public/pub/Health_Statistics/NCHS/Dataset_Documentation/NHAMCS For ease of transmission, the data files have been converted into a self- extracting compressed format. To load and expand the NHAMCS data files, do the following: first, copy the compressed file onto your hard drive into an appropriate subdirectory (for example, NHAMCS). Then go to the DOS prompt in that subdirectory and type the name of the file (ED1999) without its extension. Do the same for the OPD1999 file. In the past, the NHAMCS documentation was produced in multiple files which were then compressed into a single self-extracting file in ASCII format. For 1999, the documentation file has been produced as a single file in PDF format which can be viewed or downloaded from the above address. This file is not compressed. Size (bytes) File Name File Description Compressed Uncompressed ED1999.EXE NHAMCS Emergency department file 1,354,587 14,033,495 OPD1999.EXE NHAMCS Outpatient department file 1,471,335 19,608,855 DOC99 NHAMCS documentation file 722,929 CAUTION - Because the NHAMCS is a sample survey, the application of weights to the sample data is REQUIRED to produce national estimates of outpatient and emergency department visits, as well as to accurately assess the sampling error of statistics based on the survey data. Please refer to the documentation for instructions on how to apply the weights and to obtain relative standard errors of national estimates. IMPORTANT UPDATE: The 1999 NHAMCS public use file was updated in February, 2002 to include sample design information that will permit data users to use statistical software such as SUDAAN and STATA. The new information has been appended to the data file. A supplemental document (SUPP97-99) containing the file layout for these new variables and describing changes to the 1997, 1998, and 1999 public use files is downloadable at this web address: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHAMCS/ - 2 - For questions, suggestions, or comments concerning NHAMCS data, please contact the Ambulatory Care Statistics Branch at (301) 458-4600. These and other survey data are also available on CD-ROM and public use data tape, as well as in published summaries. For additional information on NCHS data products, contact the: Data Dissemination Branch, NCHS 3311 Toledo Road Hyattsville, MD 20782 Tel: (301) 458-4009 E-mail: nchsquery@cdc.gov Internet: http://www.cdc.gov/nchs/ - 3 -