To investigate whether pharmaceutical industry payments to physicians influences the prescribing habits of ophthalmologists, investigators compared nationwide usage of the anti-VEGF agents aflibercept (Eylea), ranibizumab (Lucentis) and bevacizumab (Avastin) with the numbers of industry payments reported.
The authors focused on these 3 medications because they have demonstrated equivalence, yet 2 of the 3 (aflibercept and ranibizumab) are heavily marketed to ophthalmologists, whereas bevacizumab - used off-label and significantly cheaper - is not.
Overall, a correlation was noted between the amount of interactions with the pharmaceutical industry and a physician’s choice of aflibercept or ranibizumab.
This is an association. It did not show that the payments caused a change in utilization. It may simply show an association, as physicians who use the drug in the first place may have more industry interactions as a result.
Data on 3,011 physicians was obtained from the CMS 2013 Medicare Provider Utilization and Payment Data: Physician and Other Supplier Public Use File and the CMS-sponsored August through December 2013 Open Payments program (Physician Payments Sunshine Act). Of 2,201,127 anti-VEGF injections, 476,885 were aflibercept, 641,963 ranibizumab, and 1,082,279 bevacizumab. Of the physicians, 1,114 received reported industry payments/benefits from Regeneron or Genentech totaling $1,320,783.60.
The ophthalmologists who accepted benefits performed a median of 53.6% (interquartile range [IQR], 23.0%-82.67%) of their injections with aflibercept or ranibizumab. The 1,867 physicians who did not receive industry benefits performed a median of 16.5% (IQR, 0%-54.0%) of their injections with aflibercept or ranibizumab (P < .001).
Analysis revealed a weak linear correlation between increasing numbers of industry payments and both the number of total injections (r = 0.24; P < 0.001), the number of aflibercept and ranibizumab injections (r = 0.32; P < 0.001), and the percentage of injections performed by each physician that were aflibercept or ranibizumab (r = 0.27; P < 0.001). In addition, there was a weak inverse correlation between number of bevacizumab injections per physician and number of payments (r = −0.27; P < .001).
An association between increased use of the two marketed drugs and amount in dollars of industry payments was found to be significant for those receiving payments of $1-$25, compared to those who received none. Interestingly, the physicians who did not receive payments showed the highest percentage of bevacizumab injections (83.5% of their total anti-VEGF prescriptions), and those in the highest bracket of payments (>$1000) used the least bevacizumab (21%).
One limitation of this study is the time period used for data extraction. Aflibercept was new to the market in 2013, and not yet approved for the indication of DME, which likely affected its utilization by ophthalmologists. Another factor is the lack of data on injections reimbursed by insurance plans other than CMS.
Despite the findings of a correlation between payments and anti-VEGF usage, the authors conclude that it is not possible to know from this study’s design if the payments were causative of the increased use, results of increased use, or simply associated with another factor.