Predicting In-Hospital and 1-Year Mortality in Geriatric Trauma Patients Using Geriatric Trauma Outcome Score

Abstract

The Geriatric Trauma Outcome Score (GTOS; [age]+ [2.5 × Injury Severity Score]+ 22 [if packed RBC transfused within ≤24 hours of admission]), was developed and validated as a prognostic indicator for in-hospital mortality in elderly trauma patients. However, GTOS neither provides information about post-discharge outcomes nor discriminates between patients dying with and without care restrictions. Isolating the latter, GTOS prediction performance was examined during admission and 1-year post discharge in a mature European trauma registry. All trauma admissions 65 years of age and older in a university hospital during 2007 to 2011 were considered. Data on age, Injury Severity Score, packed RBC transfusion within ≤24 hours, therapy restrictions, discharge disposition, and mortality were collected. In-hospital deaths with therapy restrictions and patients discharged to hospice were excluded. The GTOS was the sole predictor in a logistic regression model estimating mortality probabilities. Performance of the model was assessed by misclassification rate, Brier score, Tjur R2, and area under the curve. The study population was 1,080 patients with a median age of 75 years, mean Injury Severity Score of 10, and packed RBCs transfused in 8.2%. In-hospital mortality was 14.9% and 7.7% after exclusions. Misclassification rate fell from 14% to 6.5% and Brier score from 0.09 to 0.05, and area under the curve increased from 0.87 to 0.88. Equivalent values for the original GTOS sample were 9.8%, 0.07, and 0.82, respectively. One-year mortality follow-up showed a misclassification rate of 17.6% and Brier score of 0.13. Excluding patients with care restrictions and discharged to hospice improved GTOS performance for in-hospital mortality prediction. The GTOS is not adept at predicting 1-year mortality.