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A (Upper). Risk of bias graph: review authors’ judgements about each risk of bias item presented as percentages across all included studies. Red = high risk of bias; Yellow = unclear risk of bias; Green = low risk of bias; B (Bottom). Risk of bias summary: review authors’ judgements about each risk of bias item for each included study. Red (−) = high risk of bias; Yellow (?) = unclear risk of bias; Green (+) = low risk of bias.
