53 National Hospital Ambulatory Medical Care Survey (NHAMCS)

53.1 Organization

National Center for Health Statistics (NCHS), CDC

53.3 Description

  • Information about the provision and use of ambulatory medical care services in hospital emergency departments, outpatient departments, and ambulatory surgery centers in US
  • Data includes patient characteristics (e.g. age, sex, race/ethnicity), visit characteristics (e.g. reason for visit, diagnosis, services ordered and provided, treatments) and physician and practice characteristics

53.4 Vintage/Release Frequency

Annual since 1992

53.5 Observational Unit

Visit to described facility

53.6 Collection Methodology

  • National sample of visits to emergency departments, outpatient departments, and ambulatory surgery locations in non-institutional, general, and short-stay hospitals in US
  • Excludes Federal, military, and Veterans Administration hospitals
  • Included only hospital emergency and outpatient departments from 1992-2008, ambulatory survey in hospitals was added in 2009, and ambulatory surgery performed in freestanding ambulatory surgery centers was add in 2010 (but suspended in 2013 to develop a new sampling frame)
  • Four-stage probability sampling design used for emergency departments, outpatient departments, and ambulatory surgery locations (geographically defined areas, hospitals, clinics, and patient visits)
  • Two-stage list sample design used for freestanding ambulatory survey component (facilities and patient visits)
  • Each sampled facility selects systematic sample of patient visits from randomly selected 4-week reporting period

53.8 User Guide/Data Dictionary

Documentation available at the same website as data download

53.9 Cost

Free for download

53.10 Proposal or Application required?

No

53.11 DUA required?

No

53.12 Special Notes

  • See National Ambulatory Medical Care Survey (NAMCS) for related survey directed at the physician rather than the facility.
  • NHAMCS will cease after the collection and processing of the 2022 annual data file.
  • See https://www.cdc.gov/nchs/ahcd/notice.htm for data notices.