Time trends in the use of anti‐hypertensive medications: results from the Multi‐Ethnic Study of Atherosclerosis

Background Previous reports have suggested that new evidence of the comparative effectiveness of different medication classes from randomized controlled trials (RCTs) does not always alter treatment decisions for first‐line anti‐hypertensive therapy. Objectives To evaluate the association of RCT evidence in December 2002 from the Anti‐hypertensive and Lipid‐Lowering treatment to prevent Heart Attack Trial (ALLHAT) on use of anti‐hypertensive medications in a multi‐ethnic cohort. Methods The Multi‐Ethnic Study of Atherosclerosis (MESA) study, a prospective cohort study of 6814 adults from four ethnic groups, had four separate assessments of drug use. Users of anti‐hypertensive medications at baseline were excluded. We evaluated temporal changes in the medication class reported by new users of anti‐hypertensive medications. Results After the exclusion of anti‐hypertensive drug users at baseline, 32% of new users of anti‐hypertensive drugs seen at exam 2 were prescribed a diuretic. The publication of ALLHAT was associated with a subsequent increase in the proportion of new users taking diuretics at exam 3 compared with exam 2 (relative risk (RR): 1.31; 95% confidence interval (CI): 1.09–1.59). After the report from ALLHAT, the proportion of users of diuretics seen at exam 3 rose to 44% (starting in 2004) and 39% in exam 4 (starting in 2005). This increase in the proportion of diuretic use among new users of anti‐hypertensive medications declined slightly but could still be detected at exam 4 as compared to exam 2 (RR: 1.28; 95%CI: 1.04–1.57). Conclusions The randomized trial evidence from the ALLHAT study was temporally associated with a moderate increase in diuretic use. Copyright © 2009 John Wiley & Sons, Ltd.