Annals of Surgery

Skip Navigation LinksHome > July 2013 - Volume 258 - Issue 1 > The Comprehensive Complication Index: A Novel Continuous Sca...
Text sizing:
Annals of Surgery:
doi: 10.1097/SLA.0b013e318296c732

The Comprehensive Complication Index: A Novel Continuous Scale to Measure Surgical Morbidity

Slankamenac, Ksenija MD*; Graf, Rolf PhD*; Barkun, Jeffrey MD; Puhan, Milo A. MD, PhD; Clavien, Pierre-Alain MD, PhD*

Supplemental Author Material
Collapse Box


Objective: To develop and validate a comprehensive complication index (CCI) that integrates all events with their respective severity.

Background: Reporting of surgical complications is inconsistent and often incomplete. Most studies fail to provide information about the severity of complications, or inform only on the most severe event, ignoring events of lesser severity.

Methods: We used an established classification of complications, adopting methods from operation risk index analysis in marketing research to develop a formula that considers all complications that may occur in a patient. The weights of each grade of complication, defined as median reference values, were obtained from 472 participants, who rated 30 different complications. Validation to assess sensitivity to treatment effects and validity of the CCI was performed by 4 different approaches, based on 1299 patients.

Results: The CCI is calculated as the sum of all complications that are weighted for their severity (multiplication of the median reference values from patients and physicians). The final formula yields a continuous scale to rank the severity of any combination of complications from 0 to 100 in a single patient. The CCI was highly sensitive in detecting treatment effect differences in the context of a randomized trial (effect size detected by CCI vs conventional standardized morbidity outcomes). It also showed a negative correlation with postoperative health status (r = −0.24, P = 0.002), and high correlation with the results of patient-rated single and multiple complications on conjoint analysis (r = 0.94, P < 0.001).

Conclusions: The CCI summarizes all postoperative complications and is more sensitive than existing morbidity endpoints. It may serve as a standardized and widely applicable primary endpoint in surgical trials and other interventional fields of medicine. The CCI can be readily computed on the basis of tabulated complications according to the Clavien-Dindo classification (available at

© 2013 by Lippincott Williams & Wilkins.


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.