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Favorable bias in industry-funded drug and device studies found in review

The systematic review by the Cochrane Collaboration included studies involving medical devices.

The finding that industry-funded medical-device studies have a positive bias is important given the ongoing controversy over the Food and Drug Administration's fast-track approval process for "breakthrough" devices.
REUTERS/Jerry Lampen

Industry-funded clinical studies of drugs and medical devices are significantly more likely to produce findings that put the drug or medical device in a positive light than non-industry-funded studies, according to a new,  systematic review published Wednesday by the Cochrane Collaboration.

Yes, this is not startling news. Several other studies — including an earlier one from Cochrane — have shown that when BigPharma sponsors a drug study, the results are highly likely to be favorable to the sponsoring company’s product.

But this new review, say its authors, used a more stringent methodology for determining the influence of sponsorship on findings.

It also included, apparently for the first time, studies involving medical devices.

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The finding that industry-funded medical-device studies have a positive bias is important, especially given the ongoing controversy over the Food and Drug Administration’s fast-track approval process for “breakthrough” devices

A widespread problem

For this latest review, the Cochrane researchers examined 48 previous studies, reviews and meta-analyses involving a variety of drugs and medical devices. Many different medical problems were represented in the studies, from heart ailments to psychiatric illnesses.

The researchers found that industry-sponsored studies were 24 percent more likely to report that a drug or device was effective and 87 percent less likely to report that the product had harmful side effects than studies that were independently funded.

The authors note that drug and medical device companies often argue that their studies are more likely to have favorable results because they tend to fund studies that they know will have successful outcomes. But the Cochrane researchers discount that explanation.

“When independent investigators conduct non-industry sponsored trials, they in most cases test treatments that have been approved based on favorable industry trial results,” the researchers write. “Non-industry sponsored trials would therefore also be expected to achieve successful results.”

A more plausible explanation for the differences between industry- and non-industry-sponsored study results is “that industry achieves overly positive results through a variety of biasing choices in the design, conduct and reporting of their studies,” write the Cochrane researchers. “For example, industry protocols might include inferior comparators that will increase the chance of their product’s success. … Industry and its sponsored investigators also may selectively report favorable outcomes, fail to publish whole studies with unfavorable results, or publish studies with favorable results multiple times.”

More transparency needed

The Cochrane researchers call for more transparency in the reporting of funding sources. They also call for the publication of the raw data of studies so that each study’s findings can be independently evaluated.

In addition, they suggest that industry sponsorship should be viewed as a risk factor for bias when weighing a study’s results — especially when government and other experts are developing treatment guidelines.

“Relying on the published evidence of industry sponsored trials alone leads to too positive results, on average,” the authors write.

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The Cochrane review is behind a paywall, but you can read a summary of the study on the organization’s website.