Real and Illusory Precision Gains in Meta-Analysis to Speed Action on Carcinogens.

One should avoid benzene exposure, all other things being equal. Risk assessment can help inform human health outcomes when all other things are not equal, as when competing legal or economic interests arise. In sparse literatures where exposures may be highly deleterious and yet understudied, there is a dire need for evidence synthesis, such as meta-analysis, to maximally inform risk assessment. Here, using the analysis and approach of Scholten and colleagues from the current issue as a touch point, I describe how meta-analysis could ideally meet this aim and how it often fails to do so. Some of the current literature on transportability of causal effects is illustrative, and I describe how some of the lessons from this literature could be applied within the innovative framework of Scholten and colleagues to leverage meta-analysis within the broader decision-making framework of risk-assessment. See related article by Scholten et al., p. 751.