Abstract 39: Association Between Copay Amount And Medication Adherence For Angiotensin Receptor Neprilysin Inhibitors In Patients With Heart Failure
Background: Angiotensin receptor neprilysin inhibitors (ARNI) can significantly reduce mortality and hospitalization for patients with heart failure (HF). However, relatively high copayment costs for ARNI may contribute to shortfalls in adherence.
Methods: We conducted a retrospective cohort study of patients within a large, diverse, multi-site health system. We included patients with: an active diagnosis of HF or ejection fraction (EF) ≤ 40% on echocardiogram; a prescription for ARNI between 11/20/2020-3/31/2021; and available pharmacy or pharmacy benefit manager copayment data. Our primary exposure variable was copay amount, categorized as: $0, $0.01-$10, $10.01-$100, >$100. Our primary outcome was adherence to ARNI, defined as the proportion of days covered (PDC) ≥ 80% over 6 months. We assessed the association between copay amount and PDC using multivariable logistic regression, adjusting for the following: age, sex, race, ethnicity, insurance type, socioeconomic status (based on AHRQ SES index), EF, prior hospitalizations, and prior emergency visits.
Results: A total of 567 patients met inclusion criteria. Low copay amounts ($0.01-$10), as opposed to no copay or higher copay amounts ($10.01-$100, >$100), were more common for patients who were younger, of Black race, Hispanic/Latinx ethnicity, with Medicaid insurance, lower SES index, and lower EF (all p<0.01). Unadjusted rates of ARNI adherence varied significantly by copay amount (Figure 1A: p<0.01), and adjusted odds of ARNI adherence was significantly lower for patients with copay over $100 as compared to no copay (Figure 1B: OR 0.33, 95% CI 0.14-0.71, p<0.01). There was a graded association between copay amount and ARNI non-adherence.
Conclusions: We found lower rates of ARNI adherence for patients with higher copay amount, which persisted after multivariable adjustment. Our findings support policy-level interventions to reduce copay amounts for ARNI.
