One of the more controversial aspects of the pharmaceutical industry is the influence it has on health care providers. Many have alleged doctors receiving payments from big pharma companies increase prescriptions for certain medications, which has long been something they have denied. But for the first time, an analysis by ProPublica reveals doctors receiving payments from the medical industry do actually prescribe more name-brand medications than their colleagues who were not paid by drug and device makers, Newser reported. The more money they received, the more they prescribed brand-name medications on average.

ProPublica matched payment records from pharmaceutical and medical device makers with corresponding data on doctors’ medication choices in the Medicare program. The analysis found doctors who accepted money from drug and device makers — even if it was just a meal — are two to three times more likely to prescribe drugs at an exceptionally high rate. Doctors receiving more than $5,000 from companies during a year had the highest number of name-brand prescriptions.

The analysis also found significant state-to-state differences in the proportion of doctors who take industry money. For example, the percentage of doctors taking payments in Alabama, Nevada, Kentucky, and South Carolina was at least twice as high as in Vermont, Minnesota, Wisconsin, and Maine. Overall, however, payments seem to be widespread. Nine in 10 cardiologists nationwide who wrote at least 1,000 prescriptions for Medicare patients in 2014 were taking industry money, while 7 in 10 internists and family practitioners did, according to the analysis.

While these findings do not prove causation, it does suggest doctors have some financial incentive to prescribe the drugs that benefit pharma companies the most.

According to Dr. Richard Baron, president and chief executive of the American Board of Internal Medicine, doctors almost have to go out of their way to avoid taking payments from companies. These doctors are more likely to doubt the value of brand-name medications; but on the flip side, doctors that work to cultivate strong ties to companies are probably more receptive to brand-name drugs.

"You have the people who are going out of their way to avoid this, and you’ve for people who are, I’ll say, pretty committed and engaged to creating relationships with pharma," Baron explained. "If you are out there advocating for something, you are more likely to believe in it yourself."

Many studies have shown that generic drugs work as well as name brand drugs for most patients. They must meet Food and Drug Administration standards just the same, but aren't advertised as much as its expensive counterparts. There isn’t much of a difference between generics and brand names when it comes to patient satisfaction, either.

Dr. Kim Allan Williams Sr., president of the American College of Cardiology, believes the relationship between companies and doctors is circular. The more doctors learn about a drug’s differentiating characteristics, the more likely they are to prescribe it, he said. And as a doctor prescribes a drug more and more, the more likely they are to be selected as a speaker or consultant for the company.

"It again confirms the prevailing wisdom…that there is a relationship between payments and brand-name prescribing," Dr. Aaron Kesselheim, an associate professor at Harvard Medical School, told NPR. "This feeds into the ongoing conversation about the propriety of these sorts of relationships. Hopefully we’re getting past the point where people will say, 'Oh, there’s no evidence that these relationships change physicians’ prescribing practices.'"