National Hospital Ambulatory Medical Care Survey: 2003 outpatient department summary.

Objectives: This report describes ambulatory care visits to hospital outpatient departments (OPDs) in the United States. Statistics are shown on selected hospital, clinic, patient, and visit characteristics, as well as selected trends in OPD visits since 1993. The report highlights variation in use across the major types of OPD clinics surveyed.

Methods: The data shown in this report were collected from the 2003 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is a national probability sample survey of visits to emergency and outpatient departments of non-Federal, short stay, and general hospitals in the United States. Sample data are weighted to produce annual national estimates.

Results: During 2003, an estimated 94.6 million visits were made to hospital OPDs in the United States, about 33.1 visits per 100 persons. This rate represents a 35-percent increase since 1993, although rates have been stable since 1999. Infants under 12 months of age had a visit rate of 88.7 visits per 100 persons, a rate that increased by 23 percent since 1993. Increasing trends in OPD visit rates were found for persons 50-64 years of age (up by 30 percent), 13-21 years of age (up by 32 percent), 22-49 years of age (up by 34 percent), and 1-12 years of age (up by 71 percent). Females had higher OPD visit rates than males (39.6 compared with 26.4 visits per 100 persons), and black or African American persons had higher OPD visit rates than white persons (59.7 compared with 29.9 visits per 100 persons). Medicaid and State Children's Health Insurance Program patients used OPDs for preventive care services more frequently than private pay patients. The preventive care visit rate by Hispanic and Latino patients was twice the rate by non-Hispanic patients. Diphtheria, tetanus, and acellular pertussis (DTaP) was the most frequently provided vaccine to children under age 18 years. Between 1993-94 and 2003, the proportion of visits involving only mid-level providers increased from 5.9 to 12.6 percent of visits.