Comparative statistical performance of prehospital scoring systems with and without incorporating age for predicting multiple trauma outcomes: an observational study.

purposePrehospital trauma scoring systems have traditionally used mortality as the primary outcome, but trauma is complex condition with diverse presentations and outcomes, each of which are moderated by age. We assess the predictive performance of six prehospital trauma scoring systems across multiple outcomes, and explore the inclusion of simple age categorisations on predictive validity.

methodsThis retrospective observational study used nationwide, linked prehospital data from the National Ambulance Service (NAS) and in-hospital data from the Irish Major Trauma Audit (MTA) where the inclusion criteria are based on Injury Severity Score (ISS), length of stay and injury details. 101,114 adult trauma patients were included. Six trauma scoring systems were applied to the data and predictive performance was compared for three outcomes: major trauma (ISS > 15), MTA inclusion, and in-hospital mortality. For tools not originally including age, prior validated age categories were added and predictive performance re-assessed.

resultsAll trauma scores performed suboptimally in predicting ISS > 15 (C-statistics 0.61-0.71). For MTA inclusion, no model performed acceptably (≤ 0.64). Mortality prediction was acceptable/good (0.71-0.87). Including simple age categorisations into existing tools reduced each tool's predictive accuracy for ISS > 15, yielded modest improvements for MTA inclusion, and improved mortality prediction.

conclusionsTrauma scoring systems were most effective at predicting mortality, especially when age was included. However, they were less effective for identifying major trauma (ISS > 15) or MTA inclusion, even with age different age inclusions. The New Trauma Score, which includes oxygen saturation, showed the best overall performance for major trauma.