“…As shown in Figure 2 and Supplementary File 1, three of the selected studies were determined to have a high risk of bias due to performance (39,44), attrition (42) and/or reporting bias (39,42,44). The risk of bias for most of the papers included in the meta-analysis (34)(35)(36)(37)(38)40,41,43,45,47) was unclear; this was mainly due to the lack of data reporting the random 7 sequence generation and allocation concealment or a description of the blinding methods.…”