Systematic review of grading systems for adverse surgical outcomes

Grading scales for adverse surgical outcomes have been poorly characterized to date. The primary aim of this study was to conduct a systematic review to enumerate the various frameworks for grading adverse postoperative outcomes; our secondary objective was to outline the properties of each grading system, identifying its strengths and weaknesses.

We searched 9 databases (Africa Wide Information, Biosis, Cochrane, Embase, Global Health, LILACs, Medline, PubMed and Web of Science) from 1992 (the year the Clavien-Dindo classification system was developed) until Mar. 2, 2017, for studies that aimed to develop or improve on an already existing generalizable system for grading adverse postoperative outcomes. Study selection was duplicated as per PRISMA recommendations. Procedure-specific grading systems were excluded. We assessed the framework, strengths and weaknesses of the systems qualitatively.

We identified 9 studies on 8 adverse outcome grading systems with frameworks generalizable to any surgical procedure. Most systems have not been widely incorporated in the literature. Seven of the 8 systems were produced without including patients' perspectives. Four allowed the derivation of a composite morbidity score, which had limited tangible significance for patients.

Although each instrument identified offered its own advantages, none satisfied the need for a patient-centred tool capable of generating a composite score of all possible postoperative adverse outcomes (complications, sequelae and failure) that enables comparison of noninterventional and surgical management of disease. There is a need for development of a more comprehensive, patient-centred grading system for adverse postoperative outcomes.