Comparison of outcome of POSSUM, p-POSSUM, and cr-POSSUM scoring after elective resection of the sigmoid colon for carcinoma or complicated diverticular disease

Objective. To compare POSSUM, p- POSSUM, and cr- POSSUM- predicted mortalities with the observed postoperative mortality in patients undergoing elective sigmoid colectomy for diverticular disease (n = 121) or carcinoma (n = 120). Material and methods. The physiologic and operative severity score for the enumeration of mortality and morbidity (POSSUM) was used to identify patient-or disease-related risk factors and to calculate expected mortalities. Results. Patients with carcinoma had significantly higher POSSUM scores, but the observed mortality (1.7%) was lower than that in the diverticular disease group (3.3%). In the carcinoma group, mortality was over-predicted by all the POSSUM systems. In diverticular disease, POSSUM over-predicted mortality while p-POSSUM and cr-POSSUM under-predicted mortality. In the whole group, POSSUM over-predicted mortality. P-POSSUM and cr-POSSUM predicted mortality accurately: observed: expected (O: E) ratio 0.83. Replacing the score for malignancy with a minimum score of 1 gave overall O: E ratios of 0.37 (POSSUM), 1.04 (p-POSSUM), and 0.93 (cr-POSSUM). Conclusions. In a group of patients who underwent elective resection of the sigmoid colon for carcinoma or diverticular disease, postoperative mortality was predicted accurately by p-Possum and cr-POSSUM, especially when used without a score for malignancy. None of the POSSUM scores were predictive of disease-specific mortality.