Drug trials funded by pharma industry more likely to publish favorable results

When published results are systematically tracked for drug trials registered with ClinicalTrials.gov, those from industry-funded trials are the likeliest to be favorable to the drug in question, report researchers at Children's Hospital Boston. Publishing in the August 3 issue of the Annals of Internal Medicine, the researchers call for more public disclosure about clinical drug trials at their outset to reduce the possibility of bias in the findings.

The research team, led by Florence Bourgeois, of Children's Division of Emergency Medicine, and Kenneth Mandl, laboratory director in the Children's Hospital Informatics Program, reviewed 546 drug trials conducted between 2000 and 2006 and listed with ClinicalTrials.gov, a comprehensive, web-based federal registry of clinical trials. The analysis focused on five classes of drugs: cholesterol-lowerers, antidepressants, antipsychotics, proton-pump inhibitors and vasodilators. The researchers scanned the medical literature for publications associated with each trial, checking four separate databases and contacting trial investigators directly if necessary.

Overall, allowing for a three-year lag time from the completion of the trial, two-thirds of the trials had published results. The industry-funded trials reported positive outcomes 85% of the time, as compared with 50% for government-funded studies and 72 for those funded by non-profits or non-federal organizations. In addition, among the non-profit/non-federal trials, those that had industry contributions (nearly half) were more likely than those without to report positive outcomes (85% versus 61%). These differences were all statistically significant.