Intro: 
The objective of this study was to develop a clinically applicable nomogram to quantify the risk of 30-day mortality for patients who undergo surgery for fulminant C. difficile colitis (FCDC). 

Methods: 
After institutional board approval, the ACS-NSQIP database (2005-2015) was used to include adult patients who underwent emergency surgery (ASA ≥3) for FCDC. CPT codes were limited to total abdominal colectomies (TAC). A priori preoperative predictors of mortality were selected from the literature: age, immunosuppression, sepsis, intubation, and laboratory values. Logistic regression models were fitted and the predictive accuracy of different models were measured by calculating the area under the receiver-operating characteristic (ROC) curve as well as the AIC and BIC criteria. A cohort of 124 patients from Québec was used to validate the developed mortality calculator. 

Results: 
A total of 557 patients met our inclusion criteria and the overall mortality was 44%. The model with the best predictive accuracy included the following preoperative predictors (estimate [95%CI]): shock (0.66 [0.21;1.12), immunosuppression (1.84 [1.11;3.04]), creatinine (0.72 [0.26;1.17]), creatinine 2 (-0.11 [-0.18;0.04]), thrombocytopenia (-0.98 [-1.42;-0.54]), leukocyte count (between 4,000 and 20,000 cells/mm3 (0.44 [-0.76;1.63]), between 20,000 up to 50,000 cells/mm3 (0.34 [-0.85;-1.53]) and >50,000 cells/mm3 (3.41 [-0.22;7.04])) and age (-0.11 [-0.19;-0.02]). No statistically significant differences were found when comparing the predictive ability of the developed risk calculator with the validated ACS-NSQIP mortality risk calculator available in the database (AUC 75.61 vs. 75.14, p 0.79). External validation with the cohort of patients from Quebec showed an area under the ROC curve of 74.0% (95%CI 65.0-83.0)

Conclusion:
A clinically applicable calculator using preoperative variables to predict post-operative mortality for patients with FCDC was developed and externally validated. This calculator can help guide pre-operative decision-making.

A nomogram for prediction of mortality in patients who undergo surgery for fulminant Clostridium difficile colitis: results from the ACS-NSQIP database