Copay assistance use and prescription abandonment across race, ethnicity, or household income levels for select rheumatoid arthritis and oral oncolytic medicines

BACKGROUND: Disparities in prescription abandonment may exacerbate health inequities. Whether copay assistance is associated with changes in prescription abandonment across different patient groups is unknown. OBJECTIVE: To assess disparities in copay assistance use; prescription abandonment across race, ethnicity, or income; and association of copay use with prescription abandonment and whether it differs across race, ethnicity, or household income. METHODS: This pooled, cross-sectional study assessed claims-level prescription data linked to a consumer database containing information on race, ethnicity, and household income for commercially insured patients. The first prescription for rheumatoid arthritis (RA) or oral oncolytic medicines from 2016 to 2020 was included. Logistic regression models measured odds of copay assistance use (copay/discount cards or free-trial voucher) and prescription abandonment (prescription not filled within 30 days of health plan approval). Interaction terms for copay assistance use by race, ethnicity, and income were tested. RESULTS: The sample included 67,674 patients prescribed RA medications and 9,560 prescribed oral oncolytic medications. Copay assistance use across race, ethnicity, and income ranged from 28.2% to 31.1% (RA medicines) and 27.2% to 36.7% (oral oncolytic medicines). Among those prescribed RA medicines and not using copay assistance, Black/African American, Hispanic patients, and those with household incomes less than $50,000 were more likely to abandon prescriptions than White patients and patients with household incomes more than $200,000 (odds ratio [OR] [95% CI], P value: Black/African American: 1.17 [1.06-1.29], P < 0.01; Hispanic: 1.11 [1.01-1.22], P = 0.03; income <$50,000: 1.24 [1.11-1.37], P < 0.01). Among patients using oral oncolytic medicines and not using copay assistance, there was no racial or ethnic difference in prescription abandonment. Patients using oral oncolytics with household incomes less than $50,000 were more likely to use copay assistance (1.34 [1.12-1.61], P < 0.01), but also more likely to abandon their prescriptions if not using copay assistance (1.44 [1.12-1.85], P < 0.01). Copay assistance was associated with a 79% (RA) and 71% (oral oncolytics) lower odds of prescription abandonment (0.21 [0.19-0.24], P < 0.01; 0.29 [0.24-0.36], P < 0.01), which did not differ across race, ethnicity, or income levels (P > 0.05). CONCLUSIONS: Copay assistance has potential to narrow disparities in prescription abandonment for commercially insured Black/African American or Hispanic patients taking RA medicines and patients with household incomes less than $50,000; however, efforts to improve access to copay assistance are needed. Copay assistance, as a factor facilitating equal access to medicines, is an important consideration when evaluating policies that impact access to copay assistance programs.