Ambulatory care visits to physician offices, hospital outpatient departments, and emergency departments: United States, 1999--2000.

OBJECTIVE This report describes ambulatory care visits to physician offices, hospital outpatient departments (OPDs), and hospital emergency departments (EDs) as well as factors that may affect where care is sought. Ambulatory medical care utilization is described in terms of patient, practice/facility, and visit characteristics. Visits to office-based physicians are divided into the categories of primary care, surgical specialties, and medical specialties. METHODS Data from the 1999 and 2000 National Ambulatory Medical Care Surveys (NAMCS) and National Hospital Ambulatory Medical Care Surveys (NHAMCS) were combined to produce averaged annual estimates of ambulatory medical care utilization. To examine changes over time, current data were compared with data from the 1993 and 1994 NAMCS and NHAMCS. RESULTS Patients in the United States made an estimated 979 million visits per year in 1999 and 2000 to physician offices, hospital OPDs, and EDs, an annual rate of 3.6 visits per person. The distribution of visits by patient age, sex, race, expected source of payment, geographic region, and metropolitan statistical area (MSA) status varied across settings. The percentage of visits to office-based primary care physicians was similar for the characteristics studied, but the percentage of visits to office-based surgical and medical specialists varied considerably. Black persons had higher visit rates than white persons to hospital OPDs and EDs but lower rates to office-based surgical and medical specialists. ED visits were more likely to be patient-paid or no charge than were visits to office-based physicians. Visit rates to office-based medical specialists decreased between 1993--94 and 1999--2000. Visit rates increased for hypertension and diabetes diagnoses, as did prescription rates for central nervous system, hormonal, pain relief, and respiratory tract drugs.