Antihypertensive medication use and blood pressure control among treated older adults

The association of different antihypertensive regimens with blood pressure (BP) control is not well-described among community-dwelling older adults with low comorbidity. We examined antihypertensive use and BP control in 10 062 treated hypertensives from Australia and the United States (US) using baseline data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial. Renin-angiotensin system (RAS) drugs were the most prevalently used antihypertensive in both countries (Australia: 81.7% of all regimens; US: 62.9% of all regimens; P < .001). Diuretics were the next most commonly used antihypertensive in both countries, but were more often included in regimens of US participants (48.9%, vs 33.3% of regimens in Australia; P < .001). Among all antihypertensive classes and possible combinations, monotherapy with a RAS drug was the most common regimen in both countries, but with higher prevalence in Australian than US participants (35.9% vs 20.9%; P < .001). For both monotherapy and combination users, BP control rates across age, ethnicity, and sex were consistently lower in Australian than US participants. After adjustment for age, sex, ethnicity, and BMI, significantly lower BP control rates remained in Australian compared to US participants for the most commonly used classes and regimens (RAS blocker monotherapy: BP control = 45.5% vs 54.2%; P = .002; diuretic monotherapy: BP control = 45.2% vs 64.5%; P = .001; and RAS blocker/diuretic combo: BP control = 50.2% vs 65.6%; P = .001). Our findings highlight variation in antihypertensive use in older adults treated for hypertension, with implications for BP control. Differences in BP control that were observed may be influenced, in part, by reasons other than choice of specific regimens.