Factors Associated With Manufacturer Drug Coupon Use at US Pharmacies.

Importance: Drug companies offer coupons to lower the out-of-pocket costs for prescription drugs, yet little is known about why they do so for some drugs but not for others. Objective: To examine whether the following factors are associated with manufacturer drug coupon use: (1) patient-cost characteristics (mean per-patient cost per drug, mean patient copay); (2) drug characteristics (generics availability or "later-in-class-entrant" drugs); (3) drug-class characteristics (in-class coupon use among competitors; in-class generic competition; in-class mean cost and copay). Design Setting and Participants: This was a retrospective cohort analysis of anonymized transactional pharmacy claims sourced from retail US pharmacies from October 2017 to September 2019, supplemented with information derived from Medi-Span, Red Book, and FDA.gov. Data were analyzed from September 2020 to February 2021. Main Outcomes and Measures: The primary outcome was availability of a manufacturer's coupon. The secondary outcome was the mean proportion of transactions in which a coupon was used for each product. Results: The sample of 2501 unique brand-name prescription drugs accounted for a total of 8 995 141 claims. Manufacturers offered a coupon for 1267 (50.7%) of these drugs. When the manufacturer offered a coupon, it was used in a mean (SD) 16.3% (20.3%) of the transactions. Within a drug class, higher mean total cost per patient was positively associated with the likelihood of coupon use (odds ratio [OR], 1.03 per 10% increase; 95% CI, 1.01-1.04), but higher mean patient copay was inversely associated (OR, 0.98; 95% CI, 0.97-0.99). For drug characteristics, single-source later-in-class-entrant products were associated with a greater likelihood of coupon use compared with first entrants and multisource brands (OR, 1.44; 95% CI, 1.09-1.89). The intensity of coupon use was associated with later-in-class-entrant products and the class mean per-patient cost (4.16-percentage-point increase; 95% CI, 1.20-7.13; 0.27 per 10% increase; 95% CI, 0.09-0.44). Drugs with a new in-class brand-name competitor had greater mean coupon use compared with drugs without a new competitor (10.2% of claims with a coupon vs 5.9%). Conclusions and Relevance: In this cohort study of transactional pharmacy claims, higher mean per-patient total cost within a class was significantly associated with the likelihood of coupon use, but not patient out-of-pocket cost. Manufacturers' coupons were more likely to be used for expensive later-in-class-entrant products facing within-class competition where coupon use was prevalent.