Objective: To examine clinical and economic outcomes associated with angiotensin II receptor blockers (ARB).
Methods: Retrospective claims data were analyzed for hypertensive adults with ≥1 year follow-up from first ARB claim. Subjects were stratified into four cohorts: olmesartan (OM); valsartan (VAL); losartan (LOS); and irbesartan (IRB), which represented the full sample. Analyses were also conducted with the "limited sample," which excluded subjects with pre-existing conditions in the period before first ARB. Time to follow-up cardiac event was modeled using Cox proportional hazards regression; follow-up healthcare resource utilization and costs were examined using generalized linear models.
Results: The full and limited samples consisted of 118,700 and 65,579 subjects, respectively. Mean follow-up ranged from 861 to 933 days. Baseline characteristics including the Quan-Charlson comorbidity score differed by cohort. In both the full and limited samples, respectively, multivariate models predicted a higher adjusted risk of follow-up cardiac event for VAL cohort (hazard ratio [HR] = 1.261 and 1.242, p < 0.001), LOS cohort (HR = 1.307 and 1.178, p < 0.01), and IRB cohort (HR = 1.222 and 1.179, p ≤ 0.016) compared to OM cohort. Adjusted risk (full sample) of follow-up ambulatory and inpatient visits (all-cause and hypertension-attributable) was higher in VAL, LOS, and IRB cohorts compared to OM. Adjusted risk (limited sample) of follow-up ambulatory visits (all-cause and hypertension-attributable) was greater for VAL, LOS and IRB cohorts relative to OM, but inpatient visit risk was greater only in VAL and LOS cohorts. Compared to the OM cohort, follow-up all-cause adjusted healthcare costs (limited sample) were higher in VAL (cost ratio [CR] = 1.067, p = 0.001) and IRB cohorts (CR = 1.062, p = 0.045).
Conclusions: In this large national US health plan, treatment with OM was associated with lower risk of cardiac events and lower healthcare resource utilization and costs versus VAL, LOS, and IRB over a mean follow-up of 2.5 years. Association, rather than causality, to cardiac outcomes may be inferred from these observational claims data.