Randomization and blinding
BLIND
Patients were randomly assigned (simple randomization) to the study group using the closed envelope method. In order to conceal the allocation (1:1), consecutively numbered, opaque, sealed envelopes were used, and care was taken to ensure that they were undamaged and not see-through when held against a light source. Randomisation was carried out by an investigator who was not involved in patient eligibility, intervention delivery or data collection.Outcome assessors were blind to group allocation, and were not involved in providing the interventions (single-blind). The statisticians conducting the statistical analyses were blind to group allocation until after the analyses were completed. It was not necessary to unblind any of the participants at any time during the study.