Does the Effectiveness of a Medicine Copay Voucher Vary by Baseline Medication Out-Of-Pocket Expenses? Insights From ARTEMIS

Abstract

Background Persistence to P2Y12 inhibitors after myocardial infarction (MI) remains low. Out-of-pocket cost is cited as a factor affecting medication compliance. We examined whether a copayment intervention affected 1-year persistence to P2Y12 inhibitors and clinical outcomes. Methods and Results In an analysis of ARTEMIS (Affordability and Real-World Antiplatelet Treatment Effectiveness After Myocardial Infarction Study), patients with MI discharged on a P2Y12 inhibitor were stratified by baseline out-of-pocket medication burden: low ($0-$49 per month), intermediate ($50-$149 per month), and high (≥$150 per month). The impact of the voucher intervention on 1-year P2Y12 inhibitor persistence was examined using a logistic regression model with generalized estimating equations. We assessed the rates of major adverse cardiovascular events among the groups using a Kaplan-Meier estimator. Among 7351 MI-treated patients at 282 hospitals, 54.2% patients were in the low copay group, 32.0% in the middle copay group, and 13.8% in the high copay group. Patients in higher copay groups were more likely to have a history of prior MI, heart failure, and diabetes compared with the low copay group (all P<0.0001). Voucher use was associated with a significantly higher likelihood of 1-year P2Y12 inhibitor persistence regardless of copayment tier (low copay with versus without voucher: adjusted odds ratio [OR], 1.44 [95% CI, 1.25-1.66]; middle copay: adjusted OR, 1.63 [95% CI, 1.37-1.95]; high copay group: adjusted OR, 1.41 [95% CI, 1.05-1.87]; P interaction=0.42). Patients in the high copay group without a voucher had similar risk of 1-year major adverse cardiovascular events compared with patients in the high copay group with a voucher (adjusted hazard ratio, 0.89 [95% CI, 0.66-1.21]). Conclusions Medication copayment vouchers were associated with higher medication persistence at 1 year following an MI, regardless of out-of-pocket medication burden. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02406677.

Keywords: copay; myocardial infarction; persistence; voucher.

Figures

Figure 1. Cumulative incidence of clinical outcomes by study groups (copay status and intervention vs usual care).

(A) Cumulative incidence of major adverse cardiovascular events (MACE) after discharge for myocardial infarction (MI) by study groups (copay status and intervention vs usual care). (B) Cumulative incidence of Bleeding Academic Research Consortium (BARC) 3+ bleeding after discharge for MI by study groups (copay status and intervention vs usual care).