Classification Systems of Surgical Complexity: A Scoping Review of the Literature

A robust system for classifying the technical complexity of surgical procedures has many applications, including optimization of hospital and surgeon-level surgical performance evaluations, reimbursement, and hospital resource utilization. However, little work has been done to distinguish surgical complexity from patient- and disease-associated surgical risk.

Through a scoping review of the literature, we identified surgical subspecialty complexity classification systems which were purposed to quantify the technical complexity of a procedure and were validated with prospective or retrospective patient data.

We identified six validated surgical complexity classification systems and determined the methodology which most accurately determines surgical complexity is the level of training or expertise necessary to perform a procedure as determined by expert consensus. However, the existing literature largely validates complexity classification systems by their ability to predict morbidity and mortality which are measures of surgical risk.

A surgical complexity classification system distinct from, but used in parallel with, surgical risk has significant potential for process improvement. While the technical demands of a surgical procedure may be associated with measures of surgical risk, we propose that surgical complexity is a process measure, best represented in the literature by the level of training/expertise necessary to perform a procedure as determined through expert consensus.