Purpose: Pharmaceutical companies paid at least $3.91bn to prescribers in 2013, yet evidence indicating whether industry payments shift prescribing away from generics is limited. This study examined the association between amount of industry payments to prescribers and generic drug prescribing rates among Medicare Part D prescribers.
Methods: A cross-sectional analysis was conducted among 770 095 Medicare Part D prescribers after linking the 2013 national Open Payments data with 2013 Medicare Provider Utilization and Payment data. The exposure variable was the categorized amount of total industry payments to prescribers (i.e., meals, travel, research, and ownership). The outcome was prescriber's annual generic drug prescribing rate. Multivariable generalized linear regression models were used to examine the association between the amount of industry payments and prescriber's annual generic drug prescribing rates, controlling for prescriber's demographic and practice characteristics.
Results: In this sample, over one-third (38.0%) of Medicare Part D prescribers received industry payments in 2013. The mean annual generic drug prescribing rate was highest among prescribers receiving no payments and lowest among those receiving more than $500 of industry payments (77.5% vs. 71.3%, respectively; p < 0.001). The receipt of industry payments was independently associated with prescribers' generic drug prescribing rate; higher payments corresponded with lower generic drug prescribing rates. Other prescriber characteristics associated with higher annual generic drug prescribing rate included male sex, non-northeast region, specialty, and patient volume.
Conclusions: Receipt of industry payments was associated with a decreased rate of generic drug prescribing. How this affects patient care and total medical costs warrants further study.