“…The risk of bias for each included RCT was summarized in Figure 2 and Figure 3. For the random sequence generation, risk of bias for 11 RCTs [30,33,34,35,38,41,42,47,48,49,52] were rated as low and 12 RCTs [31,32,36,37,39,40,43,44,45,46,50,51] were rated as unclear. Only 3 RCTs [33,35,48] mentioned allocation concealment, while the remaining researches did not mention allocation concealment.…”