Although quality assessment is gaining increasing attention, there is still no consensus on how to define and grade postoperative complications. This shortcoming hampers comparison of outcome data among different centers and therapies and over time. A classification of complications published by one of the authors in 1992 was critically re-evaluated and modified to increase its accuracy and its acceptability in the surgical community. Modifications mainly focused on the manner of reporting life-threatening and permanently disabling complications. The new grading system still mostly relies on the therapy used to treat the complication. The classification was tested in a cohort of 6336 patients who underwent elective general surgery at our institution. The reproducibility and personal judgment of the classification were evaluated through an international survey with 2 questionnaires sent to 10 surgical centers worldwide. The new ranking system significantly correlated with complexity of surgery (P < 0.0001) as well as with the length of the hospital stay (P < 0.0001). A total of 144 surgeons from 10 different centers around the world and at different levels of training returned the survey. Ninety percent of the case presentations were correctly graded. The classification was considered to be simple (92% of the respondents), reproducible (91%), logical (92%), useful (90%), and comprehensive (89%). The answers of both questionnaires were not dependent on the origin of the reply and the level of training of the surgeons. The new complication classification appears reliable and may represent a compelling tool for quality assessment in surgery in all parts of the world.

Background: This is the fourth updated Enhanced Recovery After Surgery (ERAS^®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS^® protocol.Methods: A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta‐analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.Results: All recommendations on ERAS^® protocol items are based on best available evidence; good‐quality trials; meta‐analyses of good‐quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.Conclusions: The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS^® Society in this comprehensive consensus review.