MAJOR INCIDENT TRIAGE: THE CIVILIAN VALIDATION OF THE MODIFIED PHYSIOLOGICAL TRIAGE TOOL
Authors: Smith JE , Vassallo J 
Published: November 2016

Objectives & Background

Triage, the process of categorising patients based on clinical acuity, is a key principle in the effective management of a major incident (MI). Existing triage systems have so far demonstrated limited performance. The Modified Physiological Triage Tool (MPTT) was derived using a military cohort and significantly demonstrated improved performance. Within the adult civilian population, with a predominance to an older population and a blunt mechanism, no such work has been undertaken. The purpose of this study was to perform a comparative analysis and validation of the MPTT within a civilian environment.

Methods

The Trauma Audit Research Network (TARN) database was interrogated to identify all adult patients (≥18 years) treated at a single hospital between 2006 and 2014. Patients were defined as Priority One (P1) if they received a life-saving intervention from a previously defined list. Only patients with complete physiological data were included in the analysis. Using first recorded physiological data (HR/RR/GCS/SBP), patients were categorised as P1 or Not-P1 by the MPTT (12 >RR≤ 22, HR≥100, GCS<14) and existing MI triage tools. Performance characteristics of all tools were evaluated using sensitivity, specificity and AUROC, and rates of over/under-triage compared. AUROC were compared for tools with similar performance.

Results

During 2006–2014, 218,453 adult trauma patients were identified. 129,647 (59.3%) had complete data and were included: 55% male, median age 61 years and median Injury Severity Score 9. Blunt trauma predominated (96.5%), with falls<2 m the most common mechanism (53.9%). 25,452 patients (19.6%) were identified as P1. The MPTT outperformed all existing triage methods with the highest sensitivity (58.1%) and demonstrated an absolute reduction in under-triage of 44.5% when compared to the Triage Sieve. With an AUROC increase of 1.3, ROC comparison demonstrated significance between MPTT and Modified Military Sieve (X2=83.91, p<0.001), statistically supporting the use of the MPTT.

Conclusion

This study has demonstrated the performance of the MPTT (a tool derived using a military cohort) in a civilian environment, where it has been shown to outperform all existing MI triage systems in its ability to predict need for life-saving intervention. As a result of this validation, its use within a civilian major incident context is recommended.

Figure 1

Receiver Operator Characteristic Curves for MPTT & Existing MI triage tools.

Table 1

Sensitivity Analysis

ModelAUROC (95% CIs)Sensitivity (95% CIs)Specificity (95% CIs)Under-triage (1-Sens)Over-triage (1-PPV)MPTT0.646 (0.642–0.650)58.1% (57.5–58.7%)71.2% (70.9–71.4%)41.9%67.0%Military Sieve (MS)0.613 (0.609–0.617)29.0% (28.4–29.5%)93.7% (93.5–93.8%)71.0%47.2%Modified Military Sieve (MMS)0.633 (0.629–0.637)37.3% (36.7–37.9%)89.4% (89.2–89.6%)62.7%53.8%Triage Sieve (TS)0.550 (0.546–0.554)13.6% (13.2–14.0%)96.4% (96.3–96.5%)86.4%52.1%START (ST)0.618 (0.614–0.622)29.6% (29.0–30.2%)94.0% (93.8–94.1%)70.4%45.5%Careflight (CF)0.599 (0.595–0.603)24.1% (23.6–24.7%)95.7% (95.6–95.8%)75.9%42.1%

MPTT: 12<RR >= 22, HR >= 100, GCS<14. MS: 10<RR>30, HR>120, GCS<13. MMS: 12<RR>24, 40<HR>120, GCS<13. TS: 10<RR>30, HR>120. ST: RR >= 30, SBP<90, GCS<13. CF: SBP<90, GCS<13.