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).
Principal Investigator(s): United States Department of Health and Human Services. Centers for Disease Control and Prevention. National Center for Health Statistics
The National Hospital Ambulatory Medical Care Survey (NHAMCS) provides data from samples of patient records selected from emergency departments (EDs) and outpatient departments (OPDs) of a national sample of hospitals. The resulting national estimates describe the use of hospital ambulatory medical care services in the United States. For the 2007 survey, data were collected from 202 OPDs and 432 EDs. Among the variables included are age, race, and sex of the patient, reason for the visit, physician's diagnoses, cause of injury, surgical procedures (OPDs only), medication therapy, and expected source of payment. For 2007, additional updates and revisions have been made to both the emergency department and outpatient department data, including modifications to pre-existing variables pertaining but not limited to electronic medical records.
These data are freely available.
WARNING: This study is over 150MB in size and may take several minutes to download on a typical internet connection.
United States Department of Health and Human Services. Centers for Disease Control and Prevention. National Center for Health Statistics. National Hospital Ambulatory Medical Care Survey, 2007. ICPSR28442-v1. Ann Arbor, MI: Inter-university Consortium for Political and Social Research[distributor], 2010-06-24. http://doi.org/10.3886/ICPSR28442.v1
Persistent URL: http://doi.org/10.3886/ICPSR28442.v1
Scope of Study
Subject Terms: ambulatory care, emergency services, health care services, hospitalization, hospitals, injuries, medical care, medical evaluation, medical procedures, medical records, patient care, patients, payment methods, surgery, treatment
Geographic Coverage: United States
Date of Collection:
Universe: Visits to the emergency and outpatient departments of noninstitutional general and short-stay hospitals within the 50 states and the District of Columbia, which had an average length of stay of less than 30 days, or to hospitals whose specialty was general (medical or surgical) or children's general. Excluded were federal hospitals, hospital units within institutions, and hospitals with less than six beds staffed for patient use.
Data Types: administrative records data
Data Collection Notes:
Users should be aware that Stata will not allow value labels for character (string) format variables. The 2007 NHAMCS data contain a number of character variables (e.g., DIAG1, DIAG2, and DIAG3 -- physician's listed diagnosis codes).
A numeric recode version of the diagnosis variables (DIAG1R, DIAG2R, DIAG3R) has been included in the data. Value labels have been added to the SAS and SPSS setup files. Users may verify the labeling of the numeric recode variables by referring to the character (string) format variables DIAG1, DIAG2, and DIAG3. Please consult the User Guide for detailed information regarding numeric recodes for cause of injury, diagnosis, and procedure codes.
Per agreement with the National Center for Health Statistics (NCHS), ICPSR distributes the data files and text of the technical documentation for this collection as prepared by NCHS.
Detailed information regarding the use of weight variables and variance estimation is located in the User Guide.
Sample: The National Hospital Ambulatory Medical Care Survey (NHAMCS) used a four-stage probability design with samples of primary sampling units (PSUs), hospitals within PSUs, clinics within hospitals, and patient visits within clinics.
Weight: Users should use the variable PATWT when performing analyses.
Patient visit records from hospital emergency departments and outpatient departments.
Extent of Processing: 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.
Original ICPSR Release: 2010-06-24
- List all ~30 citations associated with this study
- View citations for the entire series
Most Recent Publications
- Citations exports are provided above.
Export Study-level metadata (does not include variable-level metadata)
If you're looking for collection-level metadata rather than an individual metadata record, please visit our Metadata Records page.