About two-thirds of American patients see doctors who receive payments from drug companies, but almost none of them know it.

In a collaborative study between Drexel, Stanford and Harvard, researchers found that 65 percent of participants had visited a doctor within the last year who had received payments or gifts from pharmaceutical or medical device firms.

Payments to physicians can take the form of meals, travel, gifts, speaking fees and research.

Only 5 percent of participants knew that their doctor had received these payments.

“The concern is that physicians with financial ties to drug and device companies may be more likely to recommend those companies' products to their patients, even when other choices would be better for the patient, or just as good but less costly,” said Michelle Mello, the Stanford author and a professor of law and of health research and policy.

Open Payments, which reports pharmaceutical and device industry payments to physicians, was set up as part of the Physician Payment Sunshine Act, a provision of the Affordable Care Act (ACA). The website exists to make industry payment information available to the public.

But the study found that only 12 percent of patients knew this information was accessible. The authors stated that the act’s impact is highly dependent on whether patients know about it.

“Transparency can act as a deterrent for doctors to refrain from behaviors that reflect badly on them and are also not good for their patients,” said Genevieve Pham-Kanter, the lead author and an assistant professor at Drexel’s Dornsife School of Public Health.

Drug and device companies tend to target “key opinion leaders” who are likely to influence the choices of other physicians. During the year studied, the average American physician received $193 in payments. However, the median payment for doctors visited by patients in the study was much higher, $510 for the year.

“We may be lulled into thinking this isn’t a big deal because the average payment amount across all doctors is low,” said Pham-Kanter. “But that obscures the fact that most people are seeing doctors who receive the largest payments.”

Payments vary widely across specialties. Among patients surveyed, 85 percent of those who saw an orthopedic surgeon saw a doctor who had received payments. The next highest was obstetrics and gynecology physicians at 77 percent.

“Drug companies have long known that even small gifts to physicians can be influential, and research validates the notion that they tend to induce feelings of reciprocity,” said Mello.

Despite potential changes to the ACA, Mello believes the Sunshine Act is here to stay. The current version of the American Health Care bill, which would repeal and replace the ACA, does not dismantle it.

This leaves the question of how policymakers can make information about payments to physicians more visible to patients. The authors suggested that the Centers for Medicare and Medicaid Services (CMS) could provide a one-stop shop for patients to view industry payments and other information about their providers online. Mello added that private insurers could make this information available on their “Find a Physician” websites.

“Finding the physician who is right for you depends on a lot of factors,” said Mello. “Whether a physician accepts money from industry may or may not be important to you, but my general view is that the more informed these choices are, the better they will be for patients.”