How Well Do Meta-Analyses Disclose Conflicts of Interests in Underlying Research Studies
A recent study published in JAMA reviewed 29 meta-analyses from high impact journals and found that conflicts of interests in the studies underlying the meta-analyses were rarely disclosed. The 29 meta-analyses included 11 from general medicine journals; 15 from specialty medicine journals, and 3 from the Cochrane Database of Systematic Reviews. The 29 meta-analyses reviewed an aggregate of 509 randomized controlled trials (RCTs). Of these, 318 RCTs reported funding sources with 219 (69%) industry funded. One hundred ans thirty-two of the 509 RCTs reported author conflict of interest disclosures, with 91 studies (69%) disclosing industry financial ties with one or more authors.
However, very rarely was this information reflected in the meta-analyses. Only two (7%) reported RCT funding sources and none reported RCT author-industry ties. The authors conclude “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 noted that most assessment tools for meta-analysis do not include a domain for study funding source and state: “Currently, The Cochrane Collaboration’s Risk of Bias tool includes an optional 'other sources of bias' domain, which meta-analysts could use to include information on COIs. We recommend that The Cochrane Collaboration consider formalizing the requirement to assess potential bias from COIs.”
Roseman M, Milette K, Bero LA, Coyne JC, Lexchin J, Turner EH, et al. Reporting of Conflicts of Interest in Meta-analyses of Trials of Pharmacological Treatments. JAMA: The Journal of the American Medical Association. 2011 March 9, 2011;305(10):1008-17.