Researchers are inconsistent about disclosing financial conflicts of interests, and journals are inconsistent in how they use or publish disclosure information, a novel study suggests [1].

The findings call into question the whole purpose and efficacy of a process intended to preserve integrity and eliminate bias in medical literature, investigators say.

"The system of disclosures that we have for the professional literature in medicine is not as extensive as we'd hoped," lead author Dr Kevin P Weinfurt (Duke University, Durham, NC) told.

"I think people are under the impression that disclosures are more consistent and frequent than they actually are."

The results appear online May 6, 2008 in PLoS ONE.

For their study, researchers at Duke University searched for studies about stents published in 2006, then compared prevalence, nature, and consistency of financial disclosures across the papers.

They report that of 746 papers by 2985 authors, only 17% had a disclosure statement for any author, and only 6% of authors had disclosure statements.

Strikingly, in one-third of the studies, no disclosure statement was provided, despite the fact that one or more authors had disclosed conflicts of interest in other papers.

In an interview, Weinfurt explained that it is difficult to tease out from the analysis whether authors were intentionally failing to disclose a conflict, whether they were unsure what constituted a "relevant" conflict, or whether it was the journals not requesting information or not publishing disclosure information.

"Disclosure is sort of like a new drug that's been proposed to solve a health problem," Weinfurt suggested. "In the journals, we're sort of in a situation where people are using this drug very inconsistently and not at the same dose, and very few people are giving the drug.

We're asking the question, how effective is the drug?

But the problem is, we're really not seeing a consistent use of the drug so that we can evaluate whether it's working or not."

In their review, Weinfurt et al found that the more renowned medical journals (journals that endorsed International Committee of Medical Journal Editors guidelines or that have a "higher impact factor") were the most likely to include disclosure information. More surprising statistics from the study are below.

Disclosure-statement information in stent-research papers in 2006


Occurrence
%
No disclosure statement in article
82.9
Declaration of "no conflicts of interest" in article
12.4
Disclosure of conflict of interest in article
4.7
Proportion of authors with articles with disclosure statements
6
For authors of multiple papers: no disclosure statements vs declarations of no conflicts of interest
64
For authors of multiple papers: no disclosure statements vs specific disclosures
34
For authors of multiple papers: specific disclosures vs no conflict of interest
2

But the numbers don't tell the full story. According to Weinfurt, when he and his colleagues conducted an informal Google search of authors' names who had expressly listed "no conflicts," they found that some were advisory board members for stent manufacturers or consulted for stent companies or for companies that made drugs used during or after stenting.

One person had even founded a company that makes stents, yet had not disclosed that information.

While some authors may have intentionally withheld information, Weinfurt gives them the benefit of the doubt.

"Investigators may be getting only very vague directions from the journals and doing their best to comply with them, but perhaps not including information that the public might think is appropriate.

If the journal says, please disclose any relative conflicts of interest, and if my article is evaluating the effectiveness of stents, I sincerely might not believe that the consulting work I do for a major manufacturer of medical interventions would be a conflict.

So part of the problem might be a lack of awareness on the part of investigators as to what might constitute a conflict and what might be perceived as a conflict."

Of note, just 1.3% of the research papers included in the analysis (623 papers) included information on "author contributions" (the extent to which individual authors contributed to the research and writing of the paper)—something the authors argue is a valuable corollary to understanding conflicts of interest.

"If one purpose of financial disclosures is to allow readers to assess the influence of the financial interests on the overall study, presumably readers would also need to know the role played by the authors with the financial interests," they write.

Weinfurt said he and his coauthors chose to look specifically at stents, within a one-year period, partly because of the controversies around drug-eluting stents in the past few years and partly because it is a very active area of scholarship, where people "are really looking to the research to figure out what to do."

The results of stent research will have a major influence on public health, on the multibillion-dollar stent industry, and on products/strategies that are alternatives to stents, he said.

"I think problems with disclosure are across the board, but I think the finances involved with stents and other devices do make them ripe territory for problems with conflicts of interests," he told 

1. Weinfurt KP, Seils DM, Tzeng JP, et al. Consistency of financial interest disclosures in the biomedical literature: The case of coronary stents. PLoS ONE 2008; 3:e2128. Available at: http://www.plosone.org.