Mortality prediction using TRISS methodology in the Spanish ICU Trauma Registry (RETRAUCI)

Abstract

Objectives: To validate Trauma and Injury Severity Score (TRISS) methodology as an auditing tool in the Spanish ICU Trauma Registry (RETRAUCI).

Design: A prospective, multicenter registry evaluation was carried out.

Setting: Thirteen Spanish Intensive Care Units (ICUs).

Patients: Individuals with traumatic disease and available data admitted to the participating ICUs.

Interventions: Predicted mortality using TRISS methodology was compared with that observed in the pilot phase of the RETRAUCI from November 2012 to January 2015. Discrimination was evaluated using receiver operating characteristic (ROC) curves and the corresponding areas under the curves (AUCs) (95% CI), with calibration using the Hosmer-Lemeshow (HL) goodness-of-fit test. A value of p<0.05 was considered significant.

Main variables of interest: Predicted and observed mortality.

Results: A total of 1405 patients were analyzed. The observed mortality rate was 18% (253 patients), while the predicted mortality rate was 16.9%. The area under the ROC curve was 0.889 (95% CI: 0.867-0.911). Patients with blunt trauma (n=1305) had an area under the ROC curve of 0.887 (95% CI: 0.864-0.910), and those with penetrating trauma (n=100) presented an area under the curve of 0.919 (95% CI: 0.859-0.979). In the global sample, the HL test yielded a value of 25.38 (p=0.001): 27.35 (p<0.0001) in blunt trauma and 5.91 (p=0.658) in penetrating trauma. TRISS methodology underestimated mortality in patients with low predicted mortality and overestimated mortality in patients with high predicted mortality.

Conclusions: TRISS methodology in the evaluation of severe trauma in Spanish ICUs showed good discrimination, with inadequate calibration - particularly in blunt trauma.

Keywords: Intensive Care Unit; Mortality prediction; Predicción de mortalidad; Registros de trauma; TRISS; Trauma; Trauma registry; Unidad de Cuidados Intensivos.