OBJECTIVE: To generate evidence regarding the offensive (customer acquisition) versus defensive (customer retention) motivation for pharmaceutical manufacturer coupons. DATA SOURCES AND STUDY SETTING: Retail prescriptions from IQVIA's Formulary Impact Analyzer data between 2017 and 2019. STUDY DESIGN: Ordinary least squares regression models with person, therapeutic class, drug, and time-fixed effects to measure the association between switching medications and coupon usage as well as the association between patient out-of-pocket spending and switching to a drug and using a coupon. To study switching type heterogeneity, reanalysis of associations for any type of switch, generic-brand switches, and brand-brand switches. Reestimation of baseline analyses for sodium-glucose cotransporter-2 inhibitors, anticoagulants, and inhaled corticosteroids/long-acting beta2-agonists to assess heterogeneity by drug class and market maturity. DATA COLLECTION: 1,167,132 privately insured patients that utilized at least one coupon between 2017 and 2019 for one or more prescriptions. PRINCIPAL FINDINGS: Coupon usage was associated with a 1.0 percentage point reduction in any kind of drug switch in the full sample and by 0.65-2.9 percentage points for the drug class subgroups. However, these estimates are governed by market dynamics
the probability of switching increased by 40% on the first coupon usage before declining by more than 50% on subsequent coupons. Switching after the first coupon use may be explained by systematic savings implied by coupon use
we find coupons reduced patient out-of-pocket spending by 5.00 (i.e., the majority of patient out-of-pocket costs). In subgroup analyses, coupon savings were .43 larger than average for anticoagulants, characterized by the highest levels of brand and generic competition among the considered therapeutic classes. CONCLUSIONS: Pharmaceutical manufacturers may be using coupons to acquire customers and then build brand loyalty, especially in markets with more generic competition. Antitrust authorities and other regulators should scrutinize the impact of coupons on market competitiveness and drug spending.