Development and validation of a new score for measuring post-operative complications.

PURPOSE: Assigning a numerical value to post-operative morbidity may improve its usefulness as an outcome measure. The recently developed Comprehensive Complication Index (CCI) is a step forward in this process but assigns an inappropriately high score to a combination of complications.

METHODS: We developed a new score called the complication severity score (CSS) using a mathematical process and compared it with the CCI using a questionnaire-based survey of 49 experienced gastrointestinal and hepato-pancreatico-biliary surgeons. The CSS was modified based on the results of this survey and was correlated with other patient-centered outcomes in a prospective cohort of consecutive patients undergoing elective surgery.

RESULTS: Of the nine sets of scenarios, experienced surgeons' opinion matched with CSS in 6, CSS as well as CCI in 1, and neither CSS nor CCI in 2 scenarios. Of the total 441 responses, 281 matched with CSS while 143 matched with CCI (p = 0.0001, odds ratio: 3.7; 95% CI: 2.8 to 4.8). The modified CSS significantly correlated with the post-operative length of stay (r = 0.76; 95% CI: 0.68 to 0.82; p < 0.001), the length of ICU stay (r = 0.61; 95% CI: 0.50 to 0.70; p < 0.001) and with the difference between pre-operative and post-operative quality of life scores in the physical (r = 0.29; 95% CI: 0.14 to 0.42; p < 0.001) and social (r = 0.29; 95% CI: 0.14 to 0.43; p < 0.001) domains.

CONCLUSIONS: The CSS more often matched the opinion of experienced senior surgeons compared to CCI. The modified CSS significantly correlated with other patient-centered outcomes.