Randomisation and masking
alcohol abuse
Patients were recruited by participating staff surgeons and enrolled in the study prior to elective surgery. Randomisation was performed before elective surgery, once the operation date was scheduled, in a 1:1 allocation ratio in order to balance treatment over the following factors: active smoking or clinically relevant alcohol abuse, American Society of Anaesthesiologists (ASA) physical status classification ≥ 3, Body Mass Index (BMI) ≥ 25 kg/m