Flu vaccine studies that are funded by industry are significantly more likely to be published in prestigious journals and to later be cited in the scientific literature than studies without such funding, according to a survey of 274 studies conducted by researchers from the Cochrane Vaccine Field in Italy, and published in the British Medical Journal.
A good methodology, in contrast, had little impact on such factors. The study also found few studies providing good evidence that the flu vaccine is actually effective.
In principle, a higher quality study should be published in a more prestigious journal and should be cited more frequently than a low quality study. But the researchers found no relationship between study quality and either of those factors. Instead, having a study partially or fully funded by industry was the best way to boost the prominence of a study.
Overall, the authors also found that most flu vaccine studies were of poor quality, with only 18 percent of them reporting conclusions that were actually supported by their findings (concordance).
“The study shows that one of the levers for accessing prestigious journals is the financial size of your sponsor,” said researcher Tom Jefferson. “Pharmaceutical sponsors order many reprints of studies supporting their products, often with in-house translations into many languages. They will also purchase publicity space on the journal. Many publishers openly advertise these services on their Web site.”
“It is time journals made a full disclosure of their sources of funding,” Jefferson concluded.
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The researchers also found that studies supporting the effectiveness of flu vaccines tended to be more poorly designed than studies not supporting their effectiveness. Concordance was also significantly lower in studies supporting vaccine effectiveness than in those refuting it — meaning that most studies failed to support the effectiveness of the flu vaccine.
Government-funded studies were significantly less likely to find the flu vaccine effective than industry-funded studies.
Sources for this story include: health.usnews.com.