Laparoscopic versus open colorectal surgery: cost-benefit analysis in a single-center randomized trial

Study sample No sample size appears to have been determined in the planning phase of the study to assure a certain power. Patients admitted to the authors' hospital for colorectal disease were assessed for study eligibility. Of the 588 patients assessed, 71 were excluded (14 refused to participate, 24 for infiltrating organ, 14 for cardiovascular problems, 8 for infection, 8 for respiratory problems, 2 for hepatic problems and 1 for neutropenia). Of the remaining 517 patients, 258 were allocated to LPS and 259 to open surgery.