“…Of the fifty studies, twenty-eight used randomised designs: fifteen individuallyrandomised parallel group trials [40,41,[43][44][45][46][48][49][50][51]53,55,57,64,65], eight cluster-randomised parallel group trials [25,[29][30][31]33,61,68,72], and five individually-randomised cross over or other matched trials [24,46,52,58,64]. Twenty-two were of non-randomised study design: fifteen uncontrolled before and after studies [32,34,36,37,39,47,52,54,56,57,59,62,63,67,71], six controlled before and after studies [26,38,60,66,69,…”