Prevalence, treatment, and control of hypertension among African Americans and Caucasians at primary care sites for medically under-served patients.

Context: Hypertension is a major contributor to ethnic disparities in cardiovascular disease, especially among low-income African Americans in the southeast United States.

Objective: To assess differences between African Americans and Caucasians in the prevalence, treatment, and control of hypertension in outpatient clinics for under-served patients in South Carolina.

Design: A random sample of outpatient charts on 7795 adults was abstracted from 31 primary care clinics providing health care for approximately 180,000 medically under-served patients. Variables included visit dates, blood pressures (BP), diagnosis of hypertension, and medications.

Results: Data were abstracted from outpatient medical records on 4694 African Americans (1483 men, 3195 women, 16 gender unknown, age 46.8 +/- 0.3 years) and 2540 Caucasians (1031 men, 1492 women, 17 gender unknown, age 47.7 +/- 0.4 years). The prevalence of hypertension was greater in African Americans than Caucasians (47.6% vs 31.0%, P < .001). The percentages of hypertensive African Americans and Caucasians receiving BP medications were similar (83.4% vs 81.6%, P=NS). Although African-American hypertensives were more likely than Caucasian hypertensives to receive diuretics and calcium channel blockers and less likely to receive beta-blockers, the number of BP medications was similar for both groups (1.44 +/- 0.02 vs 1.40 +/- 0.04, P=NS). Despite comparable treatment, African Americans were less likely than Caucasians to have BP controlled to <140/90 mm Hg at the most recent clinic visit (40.9% vs 46.3%, P=.01).

Conclusions: In healthcare settings for medically under-served patients, the greater prevalence and lesser control of hypertension, despite similar treatment intensity, may contribute to higher rates of cardiovascular disease among African Americans than Caucasians.