Validation of the geriatric trauma outcome scores in predicting outcomes of elderly trauma patients

•This study validated that trauma-specific tool, GTOS score had a good ability to discriminate between survivors and non-survivors in the elderly trauma patients, but GTOS II scores were no better than age alone in predicting unfavourable discharge.•When the predicted risk was higher, both models weren't well-calibrated, suggesting scope for further improvement prior to clinical utility.•The predictive ability of GTOS score in the ICU subset improved significantly when we added other variables such as co-morbidities, use of invasive ventilation and use of inotropes. We suggest refining this model by incorporating these variables. Using three patient characteristics, including age, Injury Severity Score (ISS) and transfusion within 24 h of admission (yes vs. no), the Geriatric Trauma Outcome Score (GTOS) and Geriatric Trauma Outcome Score II (GTOS II) have been developed to predict mortality and unfavourable discharge (to a nursing home or hospice facility), of those who were ≥65 years old, respectively. This study aimed to validate the GTOS and GTOS II models. For the nested-cohort requiring intensive care, we compared the GTOS scores with two ICU prognostic scores – the Acute Physiology and Chronic Health Evaluation (APACHE) III and Australian and New Zealand Risk of Death (ANZROD). All elderly trauma patients admitted to the State Trauma Unit between 2009 and 2019 were included. The discrimination ability and calibration of the GTOS and GTOS II scores were assessed by the area under the receiver-operating-characteristic (AUROC) curve and a calibration plot, respectively. Of the 57,473 trauma admissions during the study period, 15,034 (26.2%) were ≥65 years-old. The median age and ISS of the cohort were 80 (interquartile range [IQR] 72–87) and 6 (IQR 2–9), respectively; and the average observed mortality was 4.3%. The ability of the GTOS to predict mortality was good (AUROC 0.838, 95% confidence interval [CI] 0.821–0.855), and better than either age (AUROC 0.603, 95%CI 0.581–0.624) or ISS (AUROC 0.799, 95%CI 0.779–0.819) alone. The GTOS II's ability to predict unfavourable discharge was satisfactory (AUROC 0.707, 95%CI 0.696–0.719) but no better than age alone. Both GTOS and GTOS II scores over-estimated risks of the adverse outcome when the predicted risks were high. The GTOS score (AUROC 0.683, 95%CI 0.591–0.775) was also inferior to the APACHE III (AUROC 0.783, 95%CI 0.699–0.867) or ANZROD (AUROC 0.788, 95%CI 0.705–0.870) in predicting mortality for th