Pharmaceutical company–sponsored drug trials: the system is broken

Abstract

Our response to Paul Shekelle’s commentary is more an extension of his thoughts rather than a rebuttal, because we whole-heartedly agree with the points he has raised. Our study was set out to determine the magnitude of bias in a systematically evaluated body of evidence of head-tohead trials [1]. By using data from an existing Agency for Healthcare Research and Qualityesponsored comparative effectiveness review, we tried to simulate a real-world situation in which, even with considerable effort, authors were unable to detect more than one unpublished trial. Given the time and monetary restrictions for many systematic reviews, researchers frequently have to deal with such situations. Multiple studies have documented the existence of a bias that favors the sponsors’ products and misleads patients, policy makers, and health professionals alike. We did not intend to question such findings, some of which indicate massive publication bias [2,3]. We agree that this issue presents a major problem for systematic reviewsdbecause industry support always plays an important roledfrom deciding what questions are asked to how the data are interpreted and published. Studies assessing an association between sponsoring agencies and positive conclusions of individual publications, however, simply confirm the obvious, namely that there is a strong association. They fall short in answering the more intriguing question for systematic reviewers: what is the magnitude of such a bias and how does it distort conclusions in systematic reviews? Few studies have addressed this issue, particularly with a focus on head-to-head trials. Similar to our findings, other examples exist where industry sponsorship only modestly influenced results [4]. A comparison of numbers needed to treat (NNTs) derived from pooled estimates of industryand nonindustry-funded studies of migraine drugs and acute