Risk of bias assessment:
Out of the twenty-three RCTs included in the systematic review, one RCT scored as “weak” (24) seven RCTs scored as “fair” (25, 26, 35, 49, 50, 53, 55), and fifteen RCTs as “good” (27-34, 36, 46-48, 51, 52, 54). According to blinding of participants and personals or outcome assessors eight trials (24-26, 31, 35, 50, 53, 55) and four trials (24, 50, 53, 55) had high risk of bias respectively. Lack of allocation concealment was the source of risk of bias in five studies (24, 30, 46, 49, 50). One study and four studies had high risk of bias regarding incomplete outcome data (49) and selective reporting (24, 27, 32, 49). More details of the quality assessment of included RCTs is presented intable 2 .