Jewish General Hospital - Press releases

2012/08/21

Absence of guidelines makes conflicts of interest undetectable in reporting of medical research, investigators reveal

Systematic reviews can hide potential influence of drug makers on medical evidence

A lack of guidelines governing how financial conflicts of interest are reported in systematic reviews of drug studies may leave doctors, patients, and policy-makers without important information necessary for properly evaluating such studies, warns an international team of investigators led by researchers from the Lady Davis Institute at the Jewish General Hospital in Montreal. Their findings will appear tomorrow in the prestigious British Medical Journal (BMJ).

The team, led by Dr. Brett Thombs and Michelle Roseman, analyzed 151 systematic reviews published in the highly respected Cochrane Database of Systematic Reviews and found that only 20% reported the funding source of all of the drug trials under consideration. Less than 10% reported any information on whether employees of pharmaceutical companies may have authored the reports of drug trials that were reviewed.

“No single clinical trial can answer all the important questions about the potential benefits and possible risks of any drug. Thus, decisions about what drugs doctors prescribe to patients are often made on the basis of systematic reviews that synthesize the results of a large number of trials,” explained Dr. Thombs, senior investigator at the LDI and William Dawson Scholar and Associate Professor at McGill University’s Faculty of Medicine.“There are no standards, however, that require authors of these reviews to clearly reveal financial conflicts of interests in the drug studies they evaluate.”

The present study confirms the findings of previous research by this team, also led by Thombs and Roseman, which was published last year in the Journal of the American Medical Association. That study examined 29 systematic reviews that were published in top medical journals and found that only two mentioned the funding sources of the drug trials they cited.

“Together, these studies highlight the urgent need for reform of guidelines that govern the conduct of systematic reviews,” said Roseman, a McGill graduate student and the first author of both studies. “Otherwise, critical information may be hidden from people entrusted to make important decisions about our health care.”

“The goal of a systematic review is to amalgamate the broadest and most comprehensive trial data available. However, the way it is currently done, it becomes very unclear who was funding what,” said Dr. Thombs. “While it’s possible that some authors may have an interest in not disclosing funding relationships with drug makers, this problem may simply reflect a failure to appreciate the importance of reporting financial conflicts of interest. If we are to trust the conclusions of these reviews, transparency is crucial.”

The paper, “Reporting of conflicts of interest from drug trials in Cochrane reviews” is available online at http://www.bmj.com/content/345/bmj.e5155.

The Canadian Institutes of Health Research and the Fonds de la Recherche en Santé Québec provided funding that supported work on this study. In addition to Thombs and Roseman, other researchers who contributed to this study were Lisa A. Bero, Ph.D., of the University of California, San Francisco; James C. Coyne, Ph.D. of the University of Pennsylvania, Philadelphia and the University of Groningen, the Netherlands; Joel Lexchin, M.D. of York University, University of Toronto, and University Health Network, Toronto; and Erick H. Turner, M.D., of the Oregon Health and Science University, Portland.

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For further information, and to arrange interviews, contact:

Tod Hoffman
Research Communications Officer
Lady Davis Institute
Tel.: 514-340-8222 x 8661
Email: thoffman@jgh.mcgill.ca