A substantial majority of department chairs at U.S. medical schools and training hospitals have ties to the medical research industry, according to a survey conducted by doctors at Harvard Medical School (HMS) to determine the extent of those relationships.

Sixty percent of department chairs who responded to the survey, published last week in the Journal of the American Medical Association, had some form of personal relationship with private companies, ranging from collecting research funding and paid consulting to receiving free food and beverages.

The findings raised concerns about research bias at academic medical centers.

“These ties do impact the ability of medical schools to offer unbiased medical education and medical research,” said the study’s lead author, Eric G. Campbell, an associate professor at HMS. “These are the real missions of academic medical centers, and...anything that impinges on those missions is something we should pay attention to.”

The intersection between the medical industry and academia has drawn significant scrutiny in recent years, and the study authors said that determining when such interactions cross the line from fostering innovation to biasing research is far from simple.

“The influence of industry in academia is really a double-edged sword because professors may know a lot about gene expression but not a lot about manufacturing and marketing,” said study co-author Joel S. Weissman, an associate professor at HMS. “But a lot of people are starting to realize that the influence of drug companies in health care is pervasive and may be more than we want it to be.”

According to Marjorie E. Powell, senior assistant general counsel for the Pharmaceutical Research and Manufacturers of America, interactions between industry and academia have led to improved treatments for patients. Those discoveries, in turn, have outweighed the potential for conflicts of interest.

“There are a variety of built-in safeguards,” Powell said. “I don’t think patients need to be worried about doctors in academic medical centers being influenced by pharmaceutical companies.”

Campbell agreed that some interaction is beneficial, but said certain financial ties were “irresponsible.”

“There’s no justification for why a medical school department takes money to buy their faculty and students sodas and bagels,” Campbell said. “Medical school faculty, students, and residents should buy their own lunch.”

HMS faculty members cannot conduct research on technology owned or sponsored by a company that gives them more than $20,000, or in which they hold more than $30,000 in equity, according to Margaret L. Dale, the HMS dean for faculty and research integrity. They are permitted to do so if their financial interests do not exceed those limits, provided they disclose the relationship in publications and presentations.

The study authors said they surveyed department chairs because they believed their behavior would affect that of their students and colleagues.

The study authors would not divulge the results of the surveys completed by chairs at Harvard-affiliated institutions.

“The surveys we’ve done have all been anonymous,” Weissman said, “but Harvard is a huge research university, and I think you could be fairly confident that there are many, many ties with industry at Harvard.”

­—Staff writer Clifford M. Marks can be reached at cmarks@fas.harvard.edu.