BACKGROUND: To warrant the adoption or rejection of health care daily practice, it is important to establish the point at which the evidence is considered sufficiently conclusive. This process must avoid resulting from multiple testing and take account of heterogeneity across The present paper addresses the issue of whether the available evidence considered sufficiently conclusive to continue or discontinue the practice of postoperative abdominal drainage after pancreatic resection. A systematic review was conducted of randomized and non-randomized comparing outcomes after routine intra-abdominal drainage with those drainage after pancreatic resection. Studies were retrieved from the Cochrane Central Trial Register and EMBASE databases and meta-analysed cumulatively, adjusting for multiple testing and heterogeneity using the logarithm method. RESULTS: Three reports, describing, respectively, one randomized and two non-randomized studies with a comparative design, met inclusion criteria predefined for primary studies reporting on drain and complications after pancreatic resection. These studies included 89, 226 patients, respectively. The absolute differences in rates of complications in these studies were -6.4%, -9.5% and -6.3%, favour of the no-drain groups. The cumulative risk difference in major complications, adjusted for multiple testing and heterogeneity, was - 95% confidence interval of -20.2% to 4.7% (P = 0.214). CONCLUSIONS: The use of abdominal drains after pancreatic resection may result in a for major complications, but the evidence is inconclusive.