Small Effect of Pharmaceutical Industry Payments to Physicians on Medicare Prescription Habits: Using Abiraterone and Enzalutamide
Sources of Funding: none
Introduction
Abiraterone and enzalutamide are both oral chemotherapeutic agents used in metastatic prostate cancer that have been aggressively marketed to physicians since FDA approval in 2011 and 2012, respectively. We sought to investigate if there is an association between pharmaceutical industry payments to physicians and prescriptions for abiraterone and enzalutamide.
Methods
Using the Open Payments Database from 2014, we determined the number and total dollar amount of payments from industry to each urologist or oncologist who prescribed abiraterone and enzalutamide. These data were merged with the 2013 Medicare Part D Provider and Utilization Data to identify the total claim count ascribed to each physician as well as the total drug cost per prescribing physician. Drug costs (primary outcome) and claim counts (secondary outcome) were compared between prescribers who did and did not receive industry payment using Wilcoxon rank-sum tests. A Spearman Rank correlation was used to assess the relationship between industry payments and total drug costs/total claim counts for each drug.
Results
For abiraterone, we identified 4918 Open Payment recipients and 1197 prescribers, of whom 615 were both recipients and prescribers. The median payment amount to prescribers was $72 (IQR $26-$114). For enzalutamide, we identified 7820 Open Payment recipients and 412 prescribers, of whom 289 were both recipients and prescribers. The median payment amount to prescribers was 59$ (IQR $25-$148). There was no statistical association between industry payment amount and total drug costs among abiraterone prescribers (ρ = 0.07, p = 0.11) and there was a small association among enzalutamide prescribers (ρ = 0.33, p < 0.001) (Figure). _x000D_
Conclusions
Industry payments to prescribers of abiraterone and enzalutamide were common but of low amount. There was a small association between total drug costs and industry payments for prescribers of enzalutamide, but not abiraterone. Continued public reporting of industry payments to physicians will allow for further investigation of this relationship.
Funding
none
Jathin Bandari
Robert Turner
Bruce Jacobs
Benjamin Davies