Item number checklist key: (1) hypothesis/aim/objective clearly described, (2) study design well described and appropriate, (3) method of patient/control group selection clearly described, (4) characteristics of the patient/control group clearly described, (5) patients randomised to the intervention group, (6) randomisation/allocation concealed, (7) characteristics of patients lost to follow-up clearly described, (8) intervention clearly described, (9) main outcome measures clearly described, (10) attempt made to blind those measuring the primary outcome of the intervention, (11) population characteristics adequately described and controlled, (12) main findings clearly described, (13) methods of analysis appropriately and clearly described, (14) estimates of variance reported for main results, (15) analyses adjusted for different lengths of follow-up, (16) data analysed according to intention-to-treat principle, (17) conclusions supported by the results. Three levels of quality assessment of scores: ▢ low risk of bias (2), ▢ unclear risk of bias (1), ▢ high risk of bias (0).