Fig. 2: Matrix of evidence of the GROOVE tool for all meta-analyses and all included RCTs (note that refs. 182,185 are follow-up studies).

The green cells marked with 1 indicate a primary study which was included in the respective meta-analysis, the white cells indicate a primary study which was not included, and the black cells marked with X indicate a structural zero (a study that could not have been included either because it was published after the meta-analysis or because a follow-up publication has been incorporated instead).