1999 NATIONAL 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 Ambulatory Medical Care Survey with complete file documentation. The 1999 NAMCS dataset is located in: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NAMCS/ The documentation file for the 1999 NAMCS dataset is located in: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NAMCS/ For ease of transmission, the data file has been converted into a self- extracting compressed format. To load and expand the NAMCS data file, do the following: first, copy the compressed file onto your hard drive into an appropriate subdirectory (for example, NAMCS). Then go to the DOS prompt in that subdirectory and type the name of the file (NAMCS99) without its extension. In the past, the NAMCS 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 NAMCS99.EXE NAMCS dataset 1,090,214 13,805,400 DOC99.PDF NAMCS documentation file 653,419 CAUTION - Because the NAMCS is a sample survey, the application of weights to the sample data is REQUIRED to produce national estimates of office visits, as well as to accurately assess the sampling error of statistics based on the survey data. Please refer to the appropriate sections of the documentation file for information on how to apply the weights and to obtain relative standard errors of national estimates. IMPORTANT UPDATE: The 1999 NAMCS 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/NAMCS/ - 2 - For questions, suggestions, or comments concerning NAMCS 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 6525 Belcrest Rd. Hyattsville, MD 20782 Tel: (301) 458-4009 E-mail: nchsquery@cdc.gov Internet: http://www.cdc.gov/nchs/ - 3 - - 3 -