Allocation sequence concealment*
Low risk: if the allocation of participants is performed by a central independent unit, on‐site locked computer, identically looking numbered sealed opaque envelopes, drug bottles or containers prepared by an independent investigator. There must be no risk of the investigator knowing the sequence. Unclear risk: if the trial is classified as randomized but the allocation concealment process is not described. High risk: if the allocation sequence is known to the investigators who assigned participants.	Grade L / U / H
Support for judgement