Eliminating Medication Copayments for Low-income Older Adults at High Cardiovascular Risk: A Randomized Controlled Trial.

One in eight people with heart disease has poor medication adherence that, in part, is related to copayment costs. This study tested whether eliminating copayments for high-value medications among low-income older adults at high cardiovascular risk would improve clinical outcomes. This randomized 2x2 factorial trial studied 2 distinct interventions in Alberta, Canada: eliminating copayments for high value preventive medications and a self-management education and support program (reported separately). The findings for the first intervention, which waived the usual 30% copayment on 15 medication classes commonly used to reduce cardiovascular events, compared to usual copayment, is reported herein. The primary outcome was the composite of death, myocardial infarction, stroke, coronary revascularization, and cardiovascular-related hospitalizations over a three-year followup. Rates of the primary outcome and its components were compared using negative binomial regression. Secondary outcomes included quality of life(EQ-5D index score), medication adherence, and overall healthcare costs. 4,761 individuals were randomized and followed for a median of 36 months. There was no evidence of statistical interaction(p=0.99) or of a synergistic effect between the two interventions in the factorial trial with respect to the primary outcome, which allowed us to evaluate the effect of each intervention separately. The rate of the primary outcome was not reduced by copayment elimination, (521 vs 533 events, incidence rate ratio(IRR) 0.84, 95%CI 0.66 to 1.07, p=0.162). The IRR for non-fatal MI, non-fatal stroke, and cardiovascular death (0.97; 95% CI 0.67 to 1.39), death (0.94 (95%CI 0.80 to 1.11) and for cardiovascular-related hospitalizations (0.78 (95%CI 0.57 to 1.06) did not differ between groups. No significant between-group changes in quality of life over time were observed(mean difference 0.012, 95%CI -0.006 to 0.030, p=0.19). The proportion of participants who were adherent to statins was 0.72 vs 0.69 for the copayment elimination vs usual copayment groups, respectively(mean difference 0.03, 95% CI 0.006-0.06, p=0.016). Overall adjusted health care costs did not differ ($3,575, 95%CI -605 to 7,168, p=0.098). In low-income adults at high cardiovascular risk, eliminating copayments (average $35 a month) did not improve clinical outcomes or reduce healthcare costs, despite a modest improvement in adherence to medications.