National Ambulatory Medical Care Survey, 2008 (ICPSR 29921)
Published: Oct 11, 2011 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
United States Department of Health and Human Services. Centers for Disease Control and Prevention. National Center for Health Statistics
Summary View help for Summary
The National Ambulatory Medical Care Surveys (NAMCS) supply data on ambulatory medical care provided in physicians' offices. The 2008 survey contains information from 28,741 patient visits to 1,187 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 include information on the following: drugs/medications ordered, administered, or provided during office visits; 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.
Citation View help for Citation
Subject Terms View help for Subject Terms
Geographic Coverage View help for Geographic Coverage
Restrictions View help for Restrictions
In preparing the data file for this collection, the National Center for Health Statistics (NCHS) has removed direct identifiers and characteristics that might lead to identification of data subjects. As an additional precaution, NCHS requires, under section 308(d) of the Public Health Service Act (42 U.S.C. 242m), that data collected by NCHS not be used for any purpose other than statistical analysis and reporting. NCHS further requires that analysts not use the data to learn the identity of any persons or establishments and that the director of NCHS be notified if any identities are inadvertently discovered. ICPSR member institutions and other users ordering data from ICPSR are expected to adhere to these restrictions.
Distributor(s) View help for Distributor(s)
Time Period(s) View help for Time Period(s)
Date of Collection View help for Date of Collection
Data Collection Notes View help for Data Collection Notes
Per agreement with the National Center for Health Statistics (NCHS), ICPSR distributes the data file and text of the technical documentation for this collection as prepared by NCHS.
The Stata dataset (.dta file) made available by ICPSR does not contain all of the value labels found within the .do file supplied by ICPSR. Specifically, the value labels that are composed primarily of ICD-9 codes have been omitted from the .dta file. Those data users interested in applying the value labels to the dataset will be able to edit the Stata setup files, which include the aforementioned labels, provided by ICPSR.
Sample View help for Sample
The 2008 NAMCS utilized a multistage probability sample design. Primary sampling units (PSU's) were selected in the first stage; physician practices within PSU's in the second stage; and patient visits to selected physicians in the third stage.
Universe View help for 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 Source View help for Data Source
Data Type(s) View help for Data Type(s)
Mode of Data Collection View help for Mode of Data Collection
Response Rates View help for Response Rates
59.1 percent unweighted response rate, 59.6 percent weighted response rate
Original Release Date View help for Original Release Date
Version Date View help for Version Date
Version History View help for Version History
- United States Department of Health and Human Services. Centers for Disease Control and Prevention. National Center for Health Statistics. National Ambulatory Medical Care Survey, 2008. ICPSR29921-v2. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2011-10-11. http://doi.org/10.3886/ICPSR29921.v2
2011-10-11 Changes to the CPSUM variable have been made within the dataset.
2011-01-18 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Created variable labels and/or value labels.
- Created online analysis version with question text.
- Checked for undocumented or out-of-range codes.
Weight View help for Weight
Microdata file users should be fully aware of the importance of the "patient visit weight" (PATWT) and how it must be used. Information about the patient visit weight, along with a "physician-level weight" (PHYSWT), is presented in the codebook. If more information is needed, the staff of the Ambulatory Care Statistics Branch can be consulted by calling (301) 458-4600.
The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.
- The citation of this study may have changed due to the new version control system that has been implemented. Please see version history for more details.
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).