Participants and Non-participants in the Scand-Ankle study - An alcohol cessation intervention at the time of fracture surgery

Background Clinical experience indicates that patients declining participation in randomised clinical trials (RCTs) at the time of surgery are older, less healthy and of lower social status than patients accepting to participate, compromising the external validity of the RCT and bringing the non-participants in higher risk at surgery. To our knowledge, no studies exist on patients with hazardous alcohol consumption who decline participation in RCTs at the time of surgery. The aim was to compare characteristics of the participants and non-participants in the Scand-Ankle RCT. Method The Scand-Ankle study is a RCT that investigates the effect of a 6-week gold standard alcohol intervention (GSP-A) on postoperative complications in patients drinking >21 units/week and undergoing ankle fracture surgery. This study included eligible patients that declined to participate in the Scand-Ankle RCT but gave informed consent to follow-up in their medical record (N=67). Their perioperative patient characteristics were obtained from their medical record and the characteristics were compared to the patients enrolled in the study so far (N=61). Results The baseline characteristics showed no differences between participants and non-participants, but some tendencies towards the non-participants being older, having severak co-morbidities and higher ASA scores. None of the variables of interest in relation to postoperative complications (age over 70 years, comorbidity, daily smoking, ASA scores, fracture type, BMI, alcohol) were significant predictors for non-participation. Conclusion No differences were found between participants and non-participants and no patient characteristics could significantly predict participation.