Objective: To describe the changing patterns of antihypertensive medication use in the years immediately before and after the publication of the results of three major clinical trials of the treatment of hypertension in older adults.
Design: In this cohort study, adults 65 years or older were examined annually on four occasions between June 1989 and May 1992, and the use of antihypertensive medications was assessed by inventory at each visit. The four visits defined the boundaries of three study periods. For each study period, participants receiving antihypertensive therapy were either continuous users (n = 1667, 1643, and 1605, respectively) or starters (n = 157, 142, 120) of hypertensive therapy. The large clinical trials that convincingly proved the efficacy and safety of low-dose diuretic therapy in older adults were published during the latter parts of period 2 and the early parts of period 3.
Results: Among starters, the proportion initiating therapy on diuretics increased from 35.9% in period 2 to 47.5% in period 3, significantly so among women (P = .04). The proportions initiating other drugs displayed no significant trends. Among continuous users, the use of diuretics, beta-blockers, and vasodilators generally decreased over the 3-year period, while the use of calcium channel blockers and angiotensin-converting enzyme inhibitors increased significantly in each of the three periods (P < .05). The decline of 2.7% in the prevalence of diuretic use in period 1 abated during period 2 (1.8% decline), and it slowed significantly (P = .03) to almost a complete halt during period 3 (0.2% decline). The rate of increase in the use of calcium channel blockers slowed significantly (P = .01) between period 1 (+6.7%) and period 3 (+2.8%).
Conclusions: Although other factors such as cost may have been important, the temporal trends in antihypertensive drug therapy coincided in time with and may have reflected in part the influence of the major clinical trials on the patterns of clinical practice.