All: all meta-analyses with a continuous or dichotomous outcome that fulfilled the following criteria: the first meta-analysis in a review in the Cochrane Database for Systematic Reviews Issues of 2012, based on at least three studies. Ratio >5, < = 5 studies: a selection of these meta-analyses based on at most five studies, where the ratio of the largest vs. the smallest trial size was > 5. DL: DerSimonian & Laird meta-analysis method. HKSJ: Hartung-Knapp-Sidik-Jonkman meta-analysis method. DL test significant: DL p-value <0.05; HKSJ test significant: HKSJ p-value < 0.05. Note that in a few cases the HKSJ test was significant when the DL test was not.