Peer Reviewers of Medical Studies Have Conflicts of Interest 

By Crystal Lindell

How much are medical studies impacted by financial conflicts of interest? New research shows the problem may run deeper than most people realize. 

The authors of peer-reviewed studies in medical journals usually have to disclose whether or not they received money from pharmaceutical companies or medical device manufacturers. But new research published in JAMA looks at the next layer: the peer reviewers themselves.

Due to the “traditionally opaque nature of peer review,” it’s difficult to investigate the issue, but an international team of researchers studied peer reviewers at high-impact medical journals like The BMJ, JAMA, The Lancet, and The New England Journal of Medicine.

They looked specifically at nearly 2,000 U.S-based physicians who served as peer reviewers. 

What they found is both unsurprising and alarming. Between 2020 and 2022, more than half (58.9%) of the peer reviewers analyzed had received at least one industry payment. In total, the peer reviewers received a staggering $1.06 billion in industry payments. 

It should be noted that companies don’t spend that kind of money out of some noble love of medicine. No, they are doing it because it helps increase their profits or advances their interests. 

Most of that money – $1 billion or 94 percent – was paid directly to individuals or to their institutions to help fund research programs. That’s why academics who churn out studies are highly prized at universities and research institutes.

The rest of the money – $64.18 million – was in the form of general payments, which includes everything from speaker fees and “honoraria” to food, drink, lodging and travel expenses. 

The median general payment to a peer reviewer was $7,614, while the median research payment was $153,173. 

Interestingly, the average male reviewer had a significantly higher total payment ($38,959) than the average female reviewer ($19,586). 

The authors also broke down differences between medical specialties. Doctors who specialize in cardiology, rheumatology, oncology, immunology or addiction treatment were the most likely to get payments (73.5%), followed by surgeons (72%), psychiatrists (65%), hospital-based specialists (47%) and primary care physicians (38%).

Those results shed light on which fields of medicine may be more susceptible to conflicts of interests.

The study’s authors came to the only conclusion that makes sense given all this data: "Additional research and transparency regarding industry payments in the peer review process are needed."

I agree that this is clearly an issue that needs to be addressed. But we shouldn’t have to wait for more research to start taking action. We need stronger policies at medical journals to help contain the potential harm it’s causing. 

At the very least, peer reviewers should have to disclose conflicts of interest. While that may conflict with the policy of some journals to keep peer reviewers anonymous, given the potential for bias and other negative consequences, it seems the financial disclosures should take precedence. 

Since peer reviewers also have the ability to reject research before it’s even published, they should have their names and potential conflicts listed in the publications. 

Beyond that, medical journals need to start having difficult conversations about whether peer reviewers should even be allowed to review studies that involve companies or industries that pay them. 

While it may not be entirely possible in our for-profit healthcare system, that doesn’t mean it shouldn’t be explored. After all, the study did not find that 100% of peer reviewers accepted payments. So clearly some peer reviewers found a way to do the work without an obvious conflict of interest.

It isn’t just medical journals that do a poor job flagging the conflicts of peer reviewers. When PNN made a Freedom of Information Act (FOIA) request to the CDC seeking more information about the “Core Expert Group” involved in the agency’s 2016 opioid guideline, most of the documents we received back were heavily edited or redacted.

The CDC’s FOIA office said the group was exempt from our request because of “deliberative process privilege” and that disclosing their conflicts would have been “a clearly unwarranted invasion of personal privacy.”  

Why Conflicts Matter

Why do conflicts of interest matter? The easiest way to understand it is that whenever money is involved, it can potentially lead to what is essentially a boss-employee power dynamic. And typically, people don’t like to upset their bosses. 

Intuitively, most people also understand that if a medical device company funds medical device research, the researchers are incentivized to manipulate both the research methods and results in hopes of providing the funder the results they seek. 

Sometimes it’s deliberate, but sometimes it just happens on a subconscious level. People naturally favor people who give them money. However, in this case, the result of that favoritism could harm the health of millions of patients. 

In one high-profile example from 2018, a top cancer researcher failed to disclose the millions of dollars in payments he received from drug and healthcare companies.

As ProPublica and The New York Times reported, Dr. José Baselga, then-chief medical officer at Memorial Sloan Kettering Cancer Center in New York, had a number of undisclosed conflicts of interests. 

One such conflict may have led Baselga to put a positive spin on the results of two Roche-sponsored clinical trials — trials that many others had considered disappointments. He did this without disclosing the more than $3 million in consulting fees he’d received from Roche. He also left out that he had a stake in a company Roche had acquired. 

Baselga resigned just days after the news investigation came out, but journalists just don’t have the resources to constantly investigate every single researcher for conflicts of interest. That’s why medical journals must regulate the issue themselves. 

Yes, most medical journals already have policies requiring study authors to disclose conflicts of interest, but as this new research makes clear, that’s not enough. It’s past time for peer reviewers to be required to do the same. 

After all, it’s not just because the public deserves to know. Our lives could depend on it.