Racial Differences in Antihypertensive Drug Use and BP Control

Study Questions:

Are there racial differences in antihypertensive drug utilization patterns and blood pressure (BP) control by insurance status, age, sex, and presence of comorbidities?

Methods:

A total of 8,796 hypertensive individuals ≥18 years of age were identified from the National Health and Nutrition Examination Survey (2003–2012) in a repeated cross-sectional study. Hypertension was defined as systolic BP (sBP) ≥140 mm Hg, diastolic BP (dBP) ≥90 mm Hg, or a positive response to “Are you currently taking medication to lower your blood pressure?” Hypertension control was defined by Joint National Committee (JNC) 7 as: sBP <140 mm Hg and dBP <90 mm Hg for patients without chronic kidney disease (CKD) and diabetes mellitus (DM), and sBP <130 mm Hg and dBP <80 mm Hg for patients with either comorbidity. An analysis was performed comparing measures of hypertension control based on JNC 7 and proposed (JNC 8) definitions. JNC 8 eased the BP goals for older patients (≥60 years of age) without CKD and DM to sBP <150 mm Hg, dBP <90 mm Hg, and for all other patients ≥18 years of age, the goals were set at <140/90 mm Hg.

Results:

There was a significantly (p < 0.001 for each) greater percentage of blacks and Hispanics between 18-39 years, higher rates of diabetes, less CKD, nearly a 2-fold higher poverty-to-income ratio, and baseline mean sBP and mean dBP were about 3/2 mm Hg higher. During the study period, all three racial groups (whites, blacks, and Hispanics) experienced a substantial increase in hypertension treatment and control. The overall treatment rates were 73.9%, 70.8%, and 60.7%. Hypertension control rates with JNC 7 were 42.9%, 36.9%, and 31.2% for whites, blacks, and Hispanics, respectively (p < 0.001), and a >10% better control was noted in JNC 8 for each group. When stratified by insurance status, blacks (odds ratio [OR], 0.74 for insured and 0.59 for uninsured) and Hispanics (OR, 0.74 for insured and 0.58 for uninsured) persistently had lower rates of hypertension control compared with whites. Unlike black patients, Hispanics received less intensive antihypertensive therapy (OR for combination therapy, 0.77). Racial disparities also persisted in subgroups stratified by age (≥60 and <60 years of age) and presence of comorbidities, but worsened among patients <60 years of age.

Conclusions:

Black and Hispanic patients have poorer hypertension control compared with whites, and these differences are more pronounced in younger and uninsured patients. While black patients received more intensive antihypertensive therapy, Hispanics were undertreated. Future studies should further explore all aspects of these disparities to improve cardiovascular outcomes.

Perspective:

In clinical trials that provide uniform access to BP management, Hispanics achieve BP control rates similar to whites, suggesting that access and quality may explain the differences in this study. In contrast, black patients may have more aggressive hypertension with differences in the biology of the disease.


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