The Comprehensive Complication Index (CCI®): Added Value and Clinical Perspectives 3 Years "Down the Line"

To explore the added value of the comprehensive complication index (CCI) to standard assessment of postoperative morbidity, and to clarify potential controversies for its application.

The CCI was introduced about 3 years ago as a novel metric of postoperative morbidity, integrating in a single formula all complications by severity, ranging from 0 (uneventful course) to 100 (death). It remains unclear, how often the CCI adds to standard reporting of complications and how to apply it in complex postoperative courses.

CCI data were prospectively collected over a 1-year period at our institution. The proportion of patients with more than 1 complication and the severity of those complications were assessed to determine the additional value of the CCI compared to the Clavien-Dindo classification. Complex and controversial cases were presented to 90 surgeons worldwide to achieve consensus in weighing each postoperative event. Descriptive statistics were used to evaluate agreement among surgeons and to suggest solutions for consistent use of the CCI.

Complications were identified in 24% (290/1212) of the general surgical population. Of those, 44% (127/290) developed more than 1 complication by the time of discharge, and thereby CCI added information to the standard grading system of complications. Information gained by the CCI increased with the complexity of surgery and observation time.

The CCI adds information on postoperative morbidity in almost half of the patients developing complications, with particular value following extensive surgery and longer postoperative observation up to 3 months. Each single complication, independently of their inter-connection, should be included in the CCI calculation to best mirror the patients' postoperative morbidity.