“…13,41,43,57,59-67,70-72, 74-76,78,80,81,83-85,88,89,91-93,96-99,101-104,106-108,110,112,116,117 Risk of bias was judged as unclear for the final 13 studies. 42,58,68,69,73,77,79,82,95,100,105,109,111 Other sources of bias Twenty of the included RCT studies were judged as having low risk of bias in this area. 13,41,42,61,62,64,67,70,71,74,81,83,88,96,[101][102][103]106,110,112 However, a substantial number (n = 44) were classed as unclear, due to lack of sufficient information in the paper to permit detailed assessment of whether or not an important risk of bias existed, or due to insufficient rationale or evidence that an identified problem had introduced serious levels of bias to the study.…”