Evaluation and validation of the O-POSSUM score for predicting morbidity and mortality after esophagectomy: a retrospective analysis

Summary Background The accuracy of the physiological and operative severity score for the enumeration of mortality adjusted for esophagogastric surgery (O-POSSUM score) is controversial. Therefore, the aim of this study was to validate and evaluate the O‑POSSUM score with regard to its predictive power for mortality and morbidity after esophagectomy. Methods Data of 71 patients who underwent Ivor Lewis esophagectomy between 2010 and 2022 in our surgical department were analyzed retrospectively. The predicted mortality was compared with the actual mortality by binary logistic regression, and the morbidity was examined for a correlation between the Clavien–Dindo classification and the O‑POSSUM score. Results The observed mortality was 14 times higher than the predicted mortality. Thus, the O‑POSSUM score underpredicted mortality for the patient population. The area under the receiver operating characteristic curve was 0.358 (95% confidence interval 0.055 to 0.660; p = 0.291). Conclusion The O‑POSSUM score failed to identify the deceased patients. There is a very slightly positive but statistically nonsignificant correlation between the Clavien–Dindo grade and the O‑POSSUM score. The O‑POSSUM score was not found to be a reliable tool for prediction of morbidity and mortality in this study. The score should be modified or, alternatively, a new score could be invented.