Drug companies and makers of medical devices have financial ties to nearly two-thirds of U.S. medical schools and teaching hospitals, researchers found.

Serving as paid consultants or accepting industry money for free meals and drinks were among the most common practices reported by the heads of academic departments.

Drug companies and makers of medical devices often use these connections to influence doctors to use products that aren't necessarily in the patient's best interest, said Eric Campbell, the study's lead author. He is a researcher at Massachusetts General Hospital and Harvard Medical School.

Since academic department heads set the tone for appropriate conduct at their institutions, their actions signal to medical students and others that this is appropriate behavior, Campbell said.

The survey went to all 125 accredited medical schools and the nation's 15 largest teaching hospitals. About two-thirds of the department heads responded. The study gave no specific examples, nor did it name any institutions.

Many studies have examined doctor ties to drug companies. Campbell co-authored research last year that found company ties were common among hospital review boards that oversee experiments on patients.

The new study shows that drug companies "are involved in every aspect of medical care," Campbell said.

Overall, 60 percent of department heads reported some type of personal financial relationship with industry. More than one-quarter, 27 percent said they had recently served as a paid consultant. The same percentage reported serving on a company scientific advisory board; and 21 percent who headed departments of medical specialties closely related to patient care said they had served on speakers' bureaus for industry.

The results appear in Wednesday's Journal of the American Medical Association.

Alan Goldhammer of the industry group, Pharmaceutical Research and Manufacturers of America, said the study results don't mean these relationships are a problem. He said it makes sense to reach out to academic heads because they have the most expertise.

But Dr. Jerome Kassirer, a former New England Journal of Medicine editor and frequent critic of industry influence over doctors, called the study eye-opening.

"I was appalled by the results," Kassirer said. "No one knew that so many chairs of medicine and psychiatry were paid speakers. We've never had that data before."

He noted that financial ties can benefit patients when they are related to research or other scientific purposes that increase doctors' education or lead to the development of better drugs or medical products.

But they are dangerous when doctors are so beholden to the company that they withhold safety concerns or push the newest or most expensive products when they aren't necessarily best for the patient, Kassirer said.

The researchers sent surveys last year to 688 department heads at all 125 accredited U.S. medical schools and the 15 largest teaching hospitals. A total of 459 people responded, or 67 percent. Included were departments closely related to patient care, such as surgery or anesthesiology, and "nonclinical" departments more closely related to basic science.

Among those in charge of departments related to patient care, 65 percent said their departments had recently accepted industry money for continuing medical education; half reported recently getting industry money for food or drinks; 30 percent reported getting money for travel and meetings.

Overall, 67 percent said their departments had received some type industry money.

Fewer than 10 percent of chairs with personal financial relationships said those ties had any negative effects.

Dr. David Korn, a senior vice president at the Association of American Medical Colleges, which helped conduct the study, said the results aren't surprising or necessarily cause for concern.

Medical schools generally have policies governing relationships with industry to "make sure that they remained principled," Korn said.

"There is a real need to have good exchanges of information" between medical schools and industry, Korn said. "After all, when a new product is approved," the maker "knows about it better than anyone else."

Still, "gifting and favoring" are problematic, he said, and an association task force is examining the issue.

—Associated Press