How pharmaceutical industry funding affects trial outcomes: causal structures and responses.

Three recent systematic reviews have shown that pharmaceutical industry funding of clinical trials is strongly associated with pro-industry results. This article builds on those analyses, situating funding's effects in the context of the ghost-management of research and publication by pharmaceutical companies, and the creation of social ties between those companies and researchers. There are multiple demonstrated causes of the association of funding and results, ranging from trial design bias to publication bias; these are all rooted in close contact between pharmaceutical companies and much clinical research. Given these points, most proposed measures to respond to this bias are too piecemeal to be adequate.