Abstract P041: Functional Status Modifies Treatment Effectiveness in the Systolic Hypertension in the Elderly Program Trial

Abstract

Introduction: We have previously demonstrated that high blood pressure is not associated with mortality in elders with impairments in functional status. Whether functional status modifies the effectiveness of treatment to lower blood pressure is not known. Methods: The Systolic Hypertension in the Elderly Program (SHEP) was a multicenter, randomized, double-blind, placebo-controlled trial of 4,736 adults aged 60 and older with isolated systolic hypertension. Participants were randomized to chlorthalidone +/- atenolol or reserpine or matching placebo and followed for an average of 4.5 years. Functional limitation was assessed by the self-reported inability to do any one of the following activities: i) heavy work around the house, ii) walk up and down stairs, or iii) walk a half a mile. Analyses were conducted by intention-to-treat within the post-hoc subgroups. Results: There was a pattern of effect modification by functional limitation, where the association of active treatment was attenuated or inverted in persons with functional limitation compared with those without (Table). The interaction of treatment and functional limitation was strongest for the outcomes of myocardial infarction: hazard ratio = 0.57 (95% confidence interval (CI): 0.40, 0.81) and 1.33 (95% CI: 0.57, 3.07) in persons without and with functional limitation, respectively; and for mortality: 0.78 (95% CI: 0.66, 1.01) and 1.27 (95% CI: 0.83, 1.95) in persons without and with functional limitation, respectively. Conclusions: Antihypertensive therapy appears less effective in persons with self-reported functional limitation. More evidence is needed to guide optimal blood pressure control in elderly adults with functional limitation.