Combined background information for meta-analysis evaluation

Massive numbers of meta-analysis studies are being published. A Google Scholar search of "systematic review and meta-analysis" returns about 452k hits since 2014. The search was done on Jan 14, 2019. There is a need to have some way to judge the reliability of a positive claim made in a meta-analysis that uses observational studies. Our idea is to examine the quality of the observational studies used in the meta-analysis and to examine the heterogeneity of those studies. We provide background information and examples: a listing of negative studies, a simulation of p-value plots, and multiple examples of p-value plots.