Association Between Cost-Sharing and Buprenorphine Prescription Abandonment

• Published in: Journal of general internal medicine : JGIM 2024-09, Vol.39 (12), p.2160-2168
• Main Authors: Chua, Kao-Ping, Conti, Rena M., Lagisetty, Pooja, Bohnert, Amy S. B., Nuliyalu, Usha, Nguyen, Thuy D.
• Format: Article
• Language: English
• Subjects: Abandonment; Buprenorphine; Cost analysis; Dispensing; Drug stores; Evaluation; Government programs; Impact analysis; Internal Medicine; Medicare; Medicine; Medicine & Public Health; Original Research; Pharmacists; Statistical analysis
• ISSN: 0884-8734; 1525-1497; 1525-1497
• DOI: 10.1007/s11606-024-08819-2

Background Prior studies suggest cost-sharing decreases buprenorphine dispensing. However, these studies used databases that only report prescriptions filled by patients, not those that were “abandoned.” Consequently, the studies could not calculate the probability of buprenorphine prescription abandonment or evaluate whether cost-sharing is associated with abandonment. Objective To evaluate the association between cost-sharing and buprenorphine prescription abandonment. Design Cross-sectional analysis of the IQVIA Formulary Impact Analyzer, a pharmacy transaction database representing 63% of U.S. retail pharmacies. The database includes transaction records (“claims”) for prescriptions even if they are not filled. Participants Buprenorphine claims in 2022 among commercially insured and Medicare patients. Main Measures We evaluated the association between cost-sharing per 30-day supply and abandonment using logistic regression, controlling for patient characteristics, product type, and buprenorphine use in the prior 180 days. We assessed for effect modification by prior buprenorphine use. Key Results Analyses included 2,346,994 and 1,242,596 buprenorphine prescription claims for commercially insured and Medicare patients, respectively. Among these claims, mean (SD) cost-sharing per 30-day supply was $28.1 (46.4) and $8.4 (20.2), and 1.5% and 1.2% were abandoned. Each $10 increase in cost-sharing per 30-day supply was associated with a 0.09 (95% CI: 0.09, 0.10) and 0.09 (95% CI: 0.08, 0.10) percentage-point increase in abandonment among commercially insured and Medicare patients. Among commercially insured and Medicare patients without prior buprenorphine use, respectively, a $10 increase in cost-sharing per 30-day supply was associated with a 0.12 (95% CI: 0.11, 0.14) and 0.13 (95% CI: 0.07, 0.18) percentage-point higher increase in the probability of abandonment compared with patients with > 90 days of prior buprenorphine use. Conclusions Among commercially insured and Medicare patients, buprenorphine prescription abandonment is rare and only minimally associated with cost-sharing. Findings suggest elimination of buprenorphine cost-sharing should only be one component of a larger, multi-faceted campaign to increase buprenorphine dispensing.