Fig. 4

Forest plot of post-treatment effects on function, sub-grouped by treatment length of six to eight weeks and treatment length of 12 weeks. Because the scales used in Dejaco 2017 and Holmgren 2012 go in the opposite direction (i.e. higher is better) than the ones used in the other studies, the mean values were multiplied by − 1. As a rule of thumb, a standardised mean difference of 0.2 represents a small difference, 0.5 a moderate, and 0.8 a large difference. IV = inverse-variance