Invited Commentary: E Pluribus Unum for Epidemiology.

In this issue of the Journal, Amirian et al. (Am J Epidemiol. 2016;183(2):85-91) present a report from the Genetic Epidemiology of Glioma International Consortium (GLIOGENE Consortium), a new international consortium of glioma case-control studies. This report is noteworthy, because the GLIOGENE Consortium represents a new generation of epidemiologic consortia. GLIOGENE investigators have created an infrastructure that addresses important limitations of first-generation consortia efforts, which comprised a posteriori harmonization of exposure data and the inclusion of studies that did not include the same--or any--exposure data. As with these first-generation consortia efforts, the GLIOGENE Consortium embraces the primary importance of sample size, and to achieve that, the consortium tolerates different study designs that permit heterogeneity in case and control ascertainment. In contrast, however, the consortium's Glioma International Case-Control (GICC) Study incorporates systematic collection of exposure data from both cases and controls to facilitate downstream evaluation of exposure associations and gene-environment interactions. The described GICC Study thus serves as a model for future epidemiologic efforts that reflects a paradigm shift whereby studies are now being conducted with the expectation of downstream collaboration, thus demanding coordination and harmonization of apparently independent efforts at the time of study initiation rather than at study completion.