March 9, 2011

Many Drug Reviews Fail To Disclose Possible Bias

Using meta-analysis to review large batches of drug trials is believed to be the most effective method of evaluating medical products, but a new report in the Journal of the American Medical Association (JAMA) warns that bias and conflicts of interest could skew the results.

The study, which has been published in the March 9 issue of JAMA, asserts that experts to complete meta-analysis reviews often fail to disclose information on the source of a study's funding or the background of the authors completing the paper, and that could lead to problems.

An international team of researchers from the Jewish General Hospital's Lady Davis Institute for Medical Research (LDI) and McGill University in Montreal, reviewed 29 recent meta-analyses on a wide array of different drug treatment types published in "high impact" scientific and medical journals, according to a March 8 Jewish General Hospital Press release.

Those meta-studies included information from a total of 509 different trials, and in each case, the researchers noted who funded the study and whether or not the authors of each had any financial ties that could influence their research. They also took note as to which meta-analyses documented the funding providers for each of the trials reviewed.

"Only 2 of the 29 meta-analyses even mentioned the issue of who funded the original drug trials, and even those 2 did it in very obscure places in the published articles," study author Dr. Brett Thombs, a psychologist and assistant professor in the Department of Psychiatry at McGill University, said in a statement on Tuesday.

In addition, none of the meta-analyses, which according to AFP reports had been published in such well-respected journals such as JAMA, the Lancet, and the British Medical Journals, "mentioned whether researchers who conducted the trials were employed by industry or personally received money from industry," he added.

Seven of the meta-analyses Dr. Thombs and his colleagues reviewed consisted of nothing but drug trials that had been funded at least partially by the manufacturer, or who had investigators with financial ties to the drug maker. Six of the seven studies failed to disclose that information.

"Most people want their physicians to make treatment decisions based on high-quality, unbiased evidence," said first author Michelle Roseman, a graduate student at McGill University. "Researchers who conduct meta-analyses should be aware of who funds the trials they review and they should assess the risk that findings might be biased due to drug company sponsorship."

"Consumers can be more confident that drugs actually work if there is at least 1 independent evaluation that confirms this," Dr. Thombs, who according to AFP reports is pushing for policy changes that would require meta-analyses to report all potential conflicts, added. "When all existing studies are financially linked to drug makers, there is a risk that patients and their physicians may be misled."


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