The Current State of Postoperative Complication Grading Scales: A Systematic Review

To describe the existing classifications for grading postoperative complications and provide insight into their strengths and limitations.

Classifications for grading postoperative complications aim to standardize outcome reporting and improve postoperative patient care. Several grading scales exist; however, comprehensive comparisons of these systems are limited in the literature.Methods:A systematic review of the available literature that developed, adapted, compared, and/or validated scores for postoperative complications in adult patients undergoing any surgical intervention was conducted. Two researchers independently assessed the literature, excluding prognostic or predictive scores, disease-, symptom-, or procedure-specific classifications, as well as comments, letters, and replies.

A total of 79 articles were included, with 6 articles (8%) introducing a new grading scale and 7 articles (9%) proposing adaptations. The Clavien-Dindo Classification (CDC) and the Comprehensive Complication Index (CCI) were the most commonly used grading scales. Studies that validated and/or compared classifications used length of stay (LoS) (n=46, 58%), quality of life (QoL) (n=4, 5%), and/or medical costs (n=11, 14%) as outcome indicators. From the 36 studies comparing the CDC to the CCI, 33 (92%) concluded superiority of the CCI over the CDC based on specific outcome indicators such as LoS or cost. Correlation of the CCI with LoS was superior to the CDC in 26 of the 27 studies (96%) using LoS as a comparative outcome indicator.

This systematic review examined grading scales for postoperative complications, highlighting the CDC as the most used and the CCI as better correlated with outcome indicators. The authors advocate for the CCI in research while recognizing the CDC's practicality in clinical care if appropriately tailored to surgical specialties.