“…All RCTs [21, 24, 26-28, 30-32, 39] had low risk of bias for random sequence generation, incomplete outcome data and selecting reporting. The method of concealment of allocation was reported in four studies [24,26,28,31]. Four of the nine studies [26,28,31,32] performed patient blinding, and all trials demonstrated assessor blinding, with the exception of one study [32].…”