Association of Funding and Conclusions in Randomized Drug Trials

To explore whether the association between funding and conclusions in randomized drug trials reflects treatment effects or adverse events.

Observational study of 370 randomized drug trials included in meta-analyses from Cochrane reviews selected from the Cochrane Library, May 2001. From a random sample of 167 Cochrane reviews, 25 contained eligible meta-analyses (assessed a binary outcome; pooled at least 5 full-paper trials of which at least 1 reported adequate and 1 reported inadequate allocation concealment). The primary binary outcome from each meta-analysis was considered the primary outcome for all trials included in each meta-analysis. The association between funding and conclusions was analyzed by logistic regression with adjustment for treatment effect, adverse events, and additional confounding factors (methodological quality, control intervention, sample size, publication year, and place of publication). MAIN OUTCOME MEASURE: Conclusions in trials, classified into whether the experimental drug was recommended as the treatment of choice or not.