Clinical and economic outcomes associated with amlodipine/renin–angiotensin system blocker combinations

Abstract

Objectives: Since treatment regimen type can influence adherence and other outcomes, this study examined adherence, cardiovascular events, and economic outcomes in patients with hypertension treated with fixed-dose combination (FDC) amlodipine/olmesartan (AML/OM), FDC AML/benazepril (AML/BEN), and loose-dose combination AML plus angiotensin II receptor blockers (LDC AML/ARBs). Methods: Commercial health plan enrolees aged at least 18 years with index claim(s) for AML/OM, AML/BEN, or LDC AML/ARB were identified. Absence of study drug 6 months pre index, and continuous enrolment for at least 12 months post index were required. Descriptive analyses were executed to make comparisons between treatments, as well as multivariate models adjusting for baseline demographic and clinical characteristics, including propensity for assignment to study drug. Results: Descriptive results suggested mean follow-up adherence was higher in the AML/OM cohort [proportion of days covered (PDC) = 0.63] compared with the AML/BEN (PDC = 0.55; p < 0.001) and LDC AML/ARB cohorts (PDC = 0.34; p < 0.001). The proportion of individuals with an incident follow-up cardiovascular event composite was lower in the AML/OM cohort versus the AML/BEN and LDC AML/ARB cohorts (5.94% versus 7.85% and 16.89% respectively). Adjusted Cox models suggested that patients initiated on LDC AML/ARB (hazard ratio 1.35; p < 0.001), but not on AML/BEN, were at greater risk of a follow-up cardiovascular event (composite) compared with AML/OM. Adjusted generalized linear models suggested that mean follow-up per-member-per-month overall costs were higher in the AML/BEN (cost ratio = 1.169; p < 0.001; unadjusted mean cost US$780) and LDC AML/ARB cohorts (cost ratio = 1.286; p < 0.001; unadjusted mean cost US$1394) compared with the AML/OM cohort (unadjusted mean cost US$740). Conclusion: The results suggested that treatment with FDC AML/OM was associated with greater likelihood of adherence and lower overall costs than with FDC AML/BEN and LDC AML/ARB, and lower risk of cardiovascular event composite versus LDC AML/ARB.