This study is maintained and distributed by the National Archive of Computerized Data on Aging (NACDA), the aging program within ICPSR. NACDA is sponsored by the National Institute on Aging (NIA) at the National Institutes of Heath (NIH).

National Ambulatory Medical Care Survey, 2002 (ICPSR 21861)

Principal Investigator(s):


The National Ambulatory Medical Care Surveys (NAMCS) supply data on ambulatory medical care provided in physicians' offices. The 2003 survey contains information from 28,738 patient visits to 1,215 physicians' offices. Data are available on the patient's smoking habits, reason for the visit, expected source of payment, the physician's diagnosis, and the kinds of diagnostic and therapeutic services rendered. Other variables cover drugs/medications ordered, administered, or provided during office visits, with information on medication code, generic name and code, brand name, entry status, prescription status, federal controlled substance status, composition status, and related ingredient codes. Information is also included on the physician's specialization and geographic location. Demographic information on patients, such as age, sex, race, and ethnicity, was also collected.

Series: National Ambulatory Medical Care Survey Series

Access Notes

  • These data are freely available.


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National Ambulatory Medical Care Survey, 2002, - Download All Files (236.6 MB) large dataset

Study Description


U.S. Dept. of Health and Human Services, National Center for Health Statistics. NATIONAL AMBULATORY MEDICAL CARE SURVEY, 2002. ICPSR21861-v1. Hyattsville, MD: U.S. Dept. of Health and Human Services, National Center for Health Statistics [producer], 2006. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2008-03-06.

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Scope of Study

Subject Terms:   ambulatory care, doctor visits, health care services, medical care, medical evaluation, medical records, medications, patient care, patients, physicians, prescription drugs, smoking, treatment

Geographic Coverage:   United States

Time Period:  

  • 2002

Date of Collection:  

  • 2003

Universe:   Office visits made within the United States by patients of nonfederally-employed physicians who were primarily involved in office-based patient care activities, but not engaged in the specialties of radiology, pathology, or anesthesiology.

Data Types:   administrative records data

Data Collection Notes:

(1) For 2002, new drugs were added and the Ambulatory Care Drug Database was updated as necessary. It is recommended that researchers download the Drug Characteristics file, updated annually, from the Ambulatory Health Care Data Web site. The characteristics from this file can be applied by matching on drug codes to previous years of data in order to get the most accurate results when doing analysis of drug trends by therapeutic class. It is also recommended that users use the SAS program, which the National Center for Health Statistics developed. It can be adapted for use with other software, and is downloadable from their NAMCS Web site. This program will apply the new characteristics from the most current version of the drug database to previous years of data. (2) Per agreement with NCHS, ICPSR distributes the data file and text of the technical documentation for this collection as prepared by NCHS.


Sample:   The 2002 NAMCS utilized a multistage probability sample design. Primary sampling units (PSUs) were selected in the first stage, physician practices within PSUs in the second stage, and patient visits to selected physicians in the third stage.

Weight:   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 assess accurately the sampling error of statistics based on the survey data. Detailed information about the "patient visit weight" (PATWT) is located in the codebook.

Data Source:

medical records


Original ICPSR Release:  

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