Assessing complications following pancreatoduodenectomy: the Comprehensive Complication Index <i>versus</i> the Clavien–Dindo classification

Background: This study aimed to compare the accuracy of the Comprehensive Complication Index (CCI) with that of the Clavien-Dindo classification in patients undergoing pancreatoduodenectomy. Methods: A two-centre, retrospective study was undertaken that included patients who underwent pancreatoduodenectomy between 2008 and 2022. Three approaches were used to assess the two complication scores: the Spearman rank test, yielding the correlation coefficient (r), the area under the curve with 95% confidence intervals, and a mixed-effects model and a generalized mixed-effects model that yielded odds ratios and β-coefficients. Results: A total of 596 patients were included. The CCI and Clavien-Dindo classification demonstrated no correlation with 90-day mortality (r = - 0.021, 0.618; and r = -0.003, P = 0.951) but a significant correlation with length of hospital stay (r = 0.620, P &lt; 0.001; and r = 0.605, P &lt; 0.001) and with 90-day readmission rate (r = 0.148, P &lt; 0.001; and r = 0.120, P = 0.005). The accuracy of the CCI was superior to that of the Clavien-Dindo classification for length of hospital stay dichotomized at the 75th (P = 0.022) and 90th (P &lt; 0.001) percentiles. The CCI significantly improved the effect of the Clavien-Dindo classification (random effect, P &lt; 0.001) in the mixed-effects and generalized mixed-effects logistic regression analyses. Conclusion: Compared with the Clavien-Dindo classification, the CCI appeared to be more accurate in terms of its association with a prolonged hospital stay and 90-day readmission rate. The CCI should complement the Clavien-Dindo classification in clinical and research settings.