Validation of trauma scales: ISS, NISS, RTS and TRISS for predicting mortality in a Colombian population

Abstract

Background: Our purpose was to validate the performance of the ISS, NISS, RTS and TRISS scales as predictors of mortality in a population of trauma patients in a Latin American setting.

Materials and methods: Subjects older than 15 years with diagnosis of trauma, lesions in two or more body areas according to the AIS and whose initial attention was at the hospital in the first 24 h were included. The main outcome was inpatient mortality. Secondary outcomes were admission to the intensive care unit, requirement of mechanical ventilation and length of stay. A logistic regression model for hospital mortality was fitted with each of the scales as an independent variable, and its predictive accuracy was evaluated through discrimination and calibration statistics.

Results: Between January 2007 and July 2015, 4085 subjects were enrolled in the study. 84.2% (n = 3442) were male, the mean age was 36 years (SD = 16), and the most common trauma mechanism was blunt type (80.1%; n = 3273). The medians of ISS, NISS, TRISS and RTS were: 14 (IQR = 10-21), 17 (IQR = 11-27), 4.21 (IQR = 2.95-5.05) and 7.84 (IQR = 6.90-7.84), respectively. Mortality was 9.3%, and the discrimination for ISS, NISS, TRISS and RTS was: AUC 0.85, 0.89, 0.86 and 0.92, respectively. No one scale had appropriate calibration.

Conclusion: Determining the severity of trauma is an essential tool to guide treatment and establish the necessary resources for attention. In a Colombian population from a capital city, trauma scales have adequate performance for the prediction of mortality in patients with trauma.

Keywords: Mortality; Multiple trauma; Trauma Severity Indices.