A meta-analysis involves systematically combining results data across studies to produce a summary estimate of relative risk (or a weighted average or results). As more studies are published, more data become available that can be pooled together using a systematic approach. A meta-analysis serves many functions in a weight of evidence assessment, such as producing a weighted estimate of the magnitude of risk, examining and identifying potential sources of heterogeneity (between-study variation), evaluating the consistency of findings across studies, determining possible dose-response trends, and assessing publication bias. EpidStat epidemiologists, statisticians, and health scientists have published numerous meta-analyses on a wide variety of exposures and outcomes in top tier scientific and medical journals.