Physicians paid by pharmaceutical companies for meals, talks and travel had higher odds of prescribing those companies’ drugs to treat two cancer types, a University of North Carolina Lineberger Comprehensive Cancer Center–led study has found.

“Ideally, therapy choices should be based on two things, and two things only: medical evidence and patient preference,” said Aaron Mitchell, MD, a fellow in the UNC School of Medicine Division of Hematology & Oncology and the study’s lead author. “As patient advocates, we should try to eliminate any barriers to this. We saw a pretty consistent increase in prescribing of a company’s drug stemming from what we call ‘general payments,’ which don’t go directly for research, but instead are paid to physicians for consulting, meals, travel and lodging for conferences or talks. This raises the possibility that drug companies are able to influence prescribing practices through gifts to physicians.”

In oncology, the stakes are high, Mitchell said, since cancer drugs can have significant side effects and financial costs.

“This pattern is worrisome since promotional efforts by pharmaceutical companies tend to focus on newer products, which may steer providers and patients to more expensive treatments,” said the study’s senior author Stacie B. Dusetzina, PhD, a UNC Lineberger member and assistant professor in the UNC Eshelman School of Pharmacy and Gillings School of Global Public Health. “This could ultimately drive up costs for patients and taxpayers.”

Researchers analyzed prescription patterns for Medicare patients with two cancers where there are multiple treatment options – metastatic renal cell cancer and chronic myeloid leukemia. They used publicly available data reported through Open Payments, a provision of the federal Patient Protection and Affordable Care Act that required U.S. drug and device manufacturers to disclose transfers of financial value greater than $10 to physicians and teaching hospitals.

“We chose these specific drugs because they are felt to be equally efficacious based on clinical trials,” Mitchell said. “However, they do have differences in side effect profiles that a patient taking one of these drugs would notice and feel.”

Compared to physicians who didn’t receive any payments, those who received general payments for meals and lodging from a drug manufacturer had higher odds of prescribing that company’s particular drug for both metastatic renal cell carcinoma, and for chromic myeloid leukemia. For renal cell carcinoma, odds were 78 percent higher, and for chronic myeloid leukemia, odds were 29 percent higher.

The average amount that physicians received in general payments was $566 for renal cell carcinoma, and $166 for chronic myeloid leukemia.

“Even for physicians who received very small payments, we still saw a change in prescription rates,” Mitchell said. “It looks like this shakes out to be a really good buy for a drug company.”

Meanwhile, they did not find a consistent relationship for physicians who received payments from pharmaceutical companies solely for research. This doesn’t rule out the possibility of an association, however, Mitchell said.

He called for more research to uncover whether the association they found between general payments and prescription choice was a cause–and–effect relationship.

“We need to find some solution to prevent physician–industry relationships from influencing physicians in such a manner,” he added.

The preliminary findings will be presented at the American Society of Clinical Oncology Annual Meeting 2017.