Interim-analysis
hernia
SECONDARY
In March 2017, an unplanned interim analysis was conducted on the basis of data from all randomly assigned patients of whom the primary outcome was known. The study protocol had been written and approved in 2012, and since the beginning of the study, developments in incisional hernia repair methods had changed daily practice. The laparoscopic technique used in the INCH-trial without closure of the defect was getting less popular, and there was a shift toward the use of the robot, reconstruction of abdominal wall layers, and a retromuscular mesh position.Due to the variety in techniques and inconclusive evidence which repair method is superior, the research group thought an interim analysis was needed. Results indicated a probability of more than 95% that we would find no significant difference in hospital stay if we would include more patients in the trial. After considering all the evidence, the research group decided early closure of the trial for futility. Owing to the early stopping of the trial, the primary efficacy analyses and secondary efficacy analyses included all patients who had underwent incisional hernia repair. End date of the trail was April 1st 2017.