“…None of the studies fulfilled all the methodological criteria based on the sum of the 11 applicable items of the AHRQ. Most of the studies 16,18,19,23,25,35,38,40,41 were evaluated as moderate risk of bias, six studies 31,21,24,36,32,34 had high risk of bias, and five 22,33,37,39,30 had low risk of bias. The main methodological limitations representing potential risk of bias were related to non-blinding evaluators and the incomplete explanation of how missing data were handled in the sample analysis.…”