E nsuring all participants attend the follow-up visits is crucial to achieving an unbiased assessment of treatment effect. An important consideration is the feasibility and willingness of patients to participate in the trial and comply with the requirements mandated in the trial protocol. Patients’ refusal to participate may result in low enrolment and limit the generalizability of the findings.1 Patients agreeing to participate but failing to complete the trial (i.e., those deemed lost to follow-up or those who withdraw from the trial) present a major threat to the internal and the external validity of the trial. This threat to validity is most prominent when there are systematic differences between the patients who do not complete the trial in the treatment groups.2 Akl and colleagues3,4 assessed the reporting and handling of loss to follow-up and its potential impact on the estimates of treatment effect in randomized controlled trials (RCTs) in highly ranked medical journals. The authors concluded that plausible assumptions of outcomes for the participants who were lost to follow-up could change the interpretation of findings. Therefore, surgical researchers should anticipate and strive to limit the loss to follow-up at the stage of trial design, during the trial conduct and at the time of data analysis.