National Hospital Ambulatory Medical Care Survey: 2007 outpatient department summary.

OBJECTIVES This report describes ambulatory care visits to hospital outpatient departments (OPDs) in the United States. Statistics are presented on selected hospital, patient, and visit characteristics. Selected trends in OPD utilization from 1997 through 2007, as well as items new to the 2007 survey, are presented. METHODS The data presented in this report were collected in the 2007 National Hospital Ambulatory Medical Care Survey, a national probability sample survey of visits to emergency departments and OPDs of nonfederal short-stay and general hospitals in the United States. Sample data were weighted to produce annual national estimates. RESULTS During 2007, an estimated 88.9 million visits were made to hospital OPDs in the United States: about 30.0 visits per 100 persons. Females (36.7 per 100 persons) had higher OPD visit rates than males (23.0 visits per 100 persons). Black or African-American persons (58.4 visits per 100 persons) had higher OPD visit rates than white persons (26.5 visits per 100 persons). Visit rates to OPD clinics for preventive care were highest for children under 1 year of age (39.4 per 100 persons). About a third of all OPD visits (33.2%) were made by patients having Medicaid or the State Children's Health Insurance Program (SCHIP) as an expected source of payment. Medicaid or SCHIP was the source of payment for more than half (56.3%) of OPD visits made by children under age 18. The rate of preventive care visits for patients with Medicaid or SCHIP as an expected source of payment (23.1 per 100 persons) was at least four times higher than for patients having other payment sources (3.3-4.9 per 100 persons). About 82.9% of visits were made by established patients and 17.1% were made by new patients. In 2007, visits to OPDs by new and established patients averaged 5.9 visits during the past 12 months. Essential hypertension was the leading primary diagnosis at OPD visits. Moderate to severe blood pressure elevations were seen more frequently in visits by non-Hispanic or non-Latino patients than Hispanic patients and in visits by black patients compared with white patients.