Potential bias	Authors' judgement
Random sequence generation (selection bias)	High – not randomized or quasi‐randomized Unclear – states "randomized", but does not report method Low – describes method of randomizations
Allocation concealment (selection bias)	High – not concealed, open‐label trial for individually randomised, method of concealment not adequate Unclear  – details of method not reported or insufficient details Low – central allocation, sequentially numbered opaque sealed envelopes
Blinding (performance bias and detection bias)	High – personnel, participants or outcome assessors not blinded Unclear – no details reported, insufficient details reported Low – personnel, participants and outcome assessors blinded
Incomplete outcome data (attrition bias)	High – losses to follow‐up not evenly distributed across intervention and control group, high attrition rate  (20% or more for the main outcome) Unclear ‐ no details reported, insufficient details reported Low – no losses to follow‐up, losses below 20% and evenly distributed across groups, ITT analysis used. Note: for cluster‐RCTs, the loss relates to the clusters
Selective reporting (reporting bias)	High – did not fully report measured or relevant outcomes Unclear – not enough information reported to judge Low – all stated outcomes reported
Other bias	Low – no obvious other source of bias of concern to reviewers High – major source of bias such as unexplained differences in baseline characteristics