Egger's regression test produced an intercept of 2.51 (95% CI: 2.43 -2.58), which was significantly different than 0 and indicative of asymmetry in our data (t = -5.74, p-value <0.001), a finding consistent with the presence of a publication bias. A significant difference in reported summary statistics was found between subgroups (F = 7.65, p-value < 0.001). Even with the conservative approach taken to calculate effect sizes, R 2 had the greatest mean effect size of the three subgroups and was reported 64% of the time (Table , Fig. ). P-values had the lowest mean effect size and the entire 95% confidence interval fell below the overall mean effect size (1.66).