Preoperative assessment of surgical risk: creation of a scoring tool to estimate 1-year mortality after emergency abdominal surgery in the elderly patient

Background The risk of mortality after emergency general surgery (EGS) in elderly patients is prolonged beyond initial hospitalization. Our objective was to develop a preoperative scoring tool to quantify risk of 1-year mortality. Methods Three hundred ninety EGS patients aged 70 years or more were analyzed. Risk factors for 1-year mortality were identified using stepwise-forward logistic multivariate regression and weights assigned using natural logarithm of odds ratios. A geriatric emergency surgery mortality (GEM) score was derived from the aggregate of weighted scores. Leave-one-out cross-validation was performed. Results One-year mortality was 32%. Risk factors and their weights were: acute kidney injury (2), American Society of Anesthesiology class greater than or equal to 4 (2), Charlson Comorbidity Index greater than or equal to 4 (1), albumin less than 3.5 mg/dL (1), and body mass index (less than 18.5 kg/m² [1]; 18.5 to 29.9 kg/m² [0]; ≥30 kg/m² [−1]). One-year mortality was: GEM 0 to 1 (0% to 7%); GEM 2 to 5 (32% to 68%); GEM 6 to 8 (94% to 100%). C-statistics were .82 and .75 in training and validation data sets, respectively. Conclusions A simple score using 5 clinical variables predicts 1-year mortality after EGS with reasonable accuracy and assists in preoperative counseling.