JAMA: Conflicts of interests under-reported in meta-analyses
Meta-analyses of pharmacological interventions published in medical journals rarely report funding sources or author-industry financial ties, despite being disclosed in randomized controlled trial (RCT) reports, according to a study in the Journal of the American Medical Association. This has the potential to compromise the reader's understanding of the evidence.

“COIs [conflicts of interest] may influence the framing of research questions, study design, data analysis, interpretation of findings, whether to publish results and what results are reported,” the authors wrote. Compared with nonindustry-funded trials, pharmaceutical industry-funded studies more often yield results or conclusions in support of the sponsor’s drug and authors’ relationships with drug manufacturers have been linked to favorable assessments of drug efficacy and safety.”

To add to research surrounding the transparent disclosures of COIs and whether meta-analyses include them, Michelle Roseman, BA, of McGill University in Montreal, and colleagues selected 29 meta-analyses, which included 509 RCTs, for review.

The researchers looked at author-industry financial ties, author employment in each meta-analysis, study funding and whether the meta-analysis reported COIs that were within the RCTs. The study showed that only 7 percent of the meta-analyses reported RCT funding sources and none reported RCT author-industry ties or employment by the pharmaceutical industry.

None of the 29 selected meta-analyses were funded by the pharmaceutical industry, 48.3 percent reported nonindustry funding, 13.8 percent reported no study funding and 37.9 percent did not report funding sources.

Within seven of the 29 meta-analyses reviews, all RCTs had at least one form of disclosed COI, yet only one of the seven meta-analyses reported RCT funding sources and none reported RCT author-industry ties or employment.

There is general agreement on the need for complete and transparent disclosure of COI in biomedical research,” the authors wrote. “The results of the present study highlight a major gap in the reporting of COIs and suggest that, without a formal reporting policy, COIs from RCTs are unlikely to be reported when results are synthesized in meta-analyses.”

The authors urged that the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement should be updated to require study authors to report the funding sources that are included in RCTs. The authors also recommended that PRISMA should recommend that meta-analyses report author-industry financial disclosures in all RCTs or report that there was no disclosure statement.

“Risk of bias assessment in meta-analyses due to COI or other sources of potential bias in included RCTs is imperfect, and disclosure is a necessary first step, but not sufficient to mitigate the effects of COI on biomedical research,” the authors noted.

Not disclosing this information in a meta-analysis will send two messages: that the authors of the meta-analysis have not considered COI in included studies and that the meta-analysts have assessed the risk of bias related to COI in the original RCTs, concluded that COIs didn’t create biases and chose not to comment.

The researchers said this could leave readers trusting the meta-analysis conclusions when they “potentially should not."

“In either case, without acknowledgment of COI due to industry funding or author-industry financial ties from RCTs included in meta-analyses, readers’ understanding and appraisal of the evidence from the meta-analysis may be compromised,” the authors concluded.