Introduction

Science is often not objective.1 Emotional investment in particular ideas and personal interest in academic success may lead investigators to overemphasise the importance of their findings and the quality of their work. Even more serious conflicts arise when for-profit organisations, including pharmaceutical companies, provide funds for research and consulting, conduct data management and analyses, and write reports on behalf of the investigators.

Although guides to help recognise methodological weaknesses that may introduce bias are now widely available,2 3 these criteria do not protect readers against misleading interpretations of methodologically sound studies. In this article, we present a guide that provides clinicians with tools to defend against biased inferences from research studies (box).

Read methods and results only

The discussion section of research reports often offers inferences that differ from those a dispassionate reader would draw from the methods and results.4 The table gives details of two systematic reviews summarising a similar set of randomised trials assessing the effect of albumin for fluid resuscitation. The trials included in both reviews were small and methodologically weak, and their results are heterogeneous. Both the reviews provide point estimates suggesting that albumin may increase mortality and confidence intervals that include the possibility of a considerable increase in mortality. Nevertheless, one set of authors took a strong position that albumin is dangerous, the other that it is not. Their positions were consistent with the interests of funders of their reviews.5