National Ambulatory Medical Care Survey, 1973 (ICPSR 9192)

Published: Sep 12, 2008

Principal Investigator(s):
United States Department of Health and Human Services. National Center for Health Statistics


Version V1

The National Ambulatory Medical Care Surveys (NAMCS) supply data on ambulatory medical care provided in physicians' offices. These national estimates describe the utilization of ambulatory medical care and the nature and treatment of illness among the population seeking ambulatory care. The survey includes data on date of visit, reason for visit, date of birth, sex and race of patient, diagnosis, treatment, disposition of visit, and the physician's specialty.

United States Department of Health and Human Services. National Center for Health Statistics. National Ambulatory Medical Care Survey, 1973. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2008-09-12.

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Individual identifiers have been removed from the microdata tapes available from the National Center for Health Statistics. Nevertheless, under section 308(d) of the Public Health Service Act (42 U.S.C. 242m), data collected by the National Center for Health Statistics may not be used for any purpose other than for statistical reporting. ICPSR recommends to users that individual elementary unit data contained in this collection be used solely for statistical research.

1973 -- 1974


Stratified multistage probability design. In the first stage the PSUs were selected by a modified probability proportional-to-size procedure using separate sampling frames for SMSAs and for nonmetropolitan counties. The second stage consisted of a probability sample for 1973 of 1,695 practicing physicians selected from the master files maintained by the AMA and AOA. Within each PSU, all eligible physicians were stratified by nine specialty groups. The groups are: general/family practice, internal medicine, pediatrics, other medical specialties, general surgery, obstetrics/gynecology, other surgical specialties, psychiatry, and other specialties. The number of physicians in scope and agreeing to participate was 1,103. The final stage was the selection of patient visits within the annual practices of sample physicians. This involved two steps. First, the total physician sample was divided into 52 with each group randomly assigned to 1 of the 52 weeks in the survey year. Second, a systematic random sample of visits was selected by the physician during the assigned week. The total number of patient records for these visits was 29,102.

Office visits to nonfederally employed physicians classified by the American Medical Association (AMA) or the American Osteopathic Association (AOA) as "office-based patient care" (excluding specialties of anesthesiology, pathology, and radiology) from 87 Primary Sampling Units (PSUs) in the United States.

physician-enumerated forms, and induction interviews with physicians

survey data



2008-09-12 SAS, SPSS, and Stata setup files have been added to this data collection.


  • Data in this collection are available only to users at ICPSR member institutions.

  • The citation of this study may have changed due to the new version control system that has been implemented.
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