Pharma Company-Sponsored Studies Biased: Meta-analysis

Yael Waknine

December 11, 2012

Company-sponsored studies are significantly more likely to paint a rosy picture of their drug or device than independent trials, according to a new Cochrane review published in the December issue of the Cochrane Database of Systematic Reviews.

Andreas Lundh, MD, from the Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark, and colleagues found that company-sponsored trials were more likely to report favorable efficacy results (risk ratio [RR], 1.24; 95% confidence interval [CI], 1.14 - 1.35), safety profiles (RR, 1.87; 95% CI, 1.54 - 2.27), and conclusions (RR, 1.31; 95% CI, 1.20 - 1.44) compared with non–industry sponsored studies.

Although similar findings were previously reported in a review of drug studies alone, many journals continue to publish data without requiring sponsors to disclose their role in the study design, execution, and publication, the authors write.

The issue is compounded when the potential influence of study sponsorship is neglected during drug/device safety and efficacy evaluations and the development of guidelines that directly affect the manner in which clinicians practice medicine, they add.

Citing a need for improved transparency, the authors emphasize that their findings "resonate" with current calls for better access to raw data and information about how trials are carried out.

"If we agree that industry sponsorship is an important source of bias then we need to think about developing better methods for reporting, assessing and handling industry bias in systematic reviews that evaluate the effects of drugs and devices," senior author Lisa Bero, PhD, clinical professor at the University of California, San Francisco, School of Pharmacy and Institute for Health Policy Studies, said in a Cochrane Collaboration news release.

"Unexplained Bias"

For the study, researchers analyzed 48 current literature reports of cross-sectional studies, cohort studies, systematic reviews, and meta-analyses that quantitatively compared primary research of drug or medical device studies sponsored by the pharmaceutical or device industry with studies that had other sources of sponsorship.

The reports covered drugs and devices used for a wide variety of diseases and conditions that ranged from heart ailments to psychiatric abnormalities, comparing them with placebo or other treatments. Papers without quantitative data were excluded from the review, as were those focused on tobacco/food/chemical industries, herbal supplement efficacy, or medical procedures.

Although 10 papers reported on sponsorship and effect size, they could not be pooled because of data-reporting incompatibilities. Results were heterogenous: 5 papers found larger effect sizes in industry-sponsored studies compared with non–industry sponsored studies and 5 found no differences between them.

No differences were found between industry-sponsored and non–industry sponsored studies with respect to risk of bias from sequence generation, allocation concealment, and follow-up. However, industry-sponsored studies reported lower risks for bias from blinding (RR, 1.32; 95% CI, 1.05 - 1.65) and were more likely to demonstrate discrepancies between results and conclusions (RR, 0.84; 95% CI, 0.70 - 1.01).

"Our analysis suggests that industry sponsored drug and device studies are more often favorable to the sponsor's products than non-industry sponsored drug and device studies due to biases that cannot be explained by standard 'Risk of bias' assessment tools," the authors write, noting that the findings support current calls for release of full protocol information and raw data to combat "too positive results" when using company-sponsored data to conduct systematic reviews and formulate clinical guidelines.

The study was supported in part by a grant from the Canadian Institutes of Health Research, Canada. Three coauthors are authors of the some of the previous reviews and included studies. In 2007, one coauthor was retained by a law firm representing Apotex to provide expert testimony about the effects of promotion on the sales of medications, and from 2007 to 2008, he was retained as an expert witness by the Canadian federal government in its defense of a lawsuit challenging the ban on direct-to-consumer advertising of prescription drugs in Canada. In 2010, he was a consultant to a law firm acting for the family of a patient who died from an alleged side effect of a drug made by Allergan. He is also on the management group of Healthy Skepticism Inc and the chair of the Health Action International - Europe Association Board. The authors have disclosed no other relevant financial relationships.

Cochrane Database Syst Rev. 2012;12. Abstract