Inclusion Criteria: NAMCS limits providers to the 50 states and the District of Columbia. Visits to physicians in primary care specialties are included.
Exclusion Criteria: NAMCS excludes visits to physicians in the specialties of anesthesiology, pathology, and radiology.
Visits to Nurse Practitioners, Certified Nurse Midwives and Physician Assistants in Community Health Centers were gathered beginning in 2006 but were excluded from this analysis to allow for trends including 2005 data.
Missing Data: Due to small sample sizes and the reliability of some estimates, data is not available for all years for all population categories displayed on this page.
This measure is calculated by the CDC/NCHS/DHCS from the National Ambulatory Medical Care Survey (NAMCS) data.