Fig. 4

Forest plot of the studies included in the main meta-analysis for known-groups validity which used 15° as the starting angle. ^aGroup numbers (i.e. “Total”) for both groups have been divided by the number of times each group has been included in the meta-analysis. ^bGroup number (i.e. “Total”) for the control group only has been divided by the number of times the group has been included in the meta-analysis