Evaluation of mechanism of injury criteria for field triage of occupants involved in motor vehicle collisions

Abstract

Objective: The mechanism of injury (MOI) criteria assist in determining which patients are at high risk of severe injury and would benefit from direct transport to a trauma center. The goal of this study was to determine whether the prognostic performance of the Centers for Disease Control's (CDC) MOI criteria for motor vehicle collisions (MVCs) has changed during the decade since the guidelines were approved. Secondary objectives were to evaluate the performance of these criteria for different age groups and evaluate potential criteria that are not currently in the guidelines.

Methods: Data were obtained from NASS and Crash Investigation Sampling System (CISS) for 2000-2009 and 2010-2019. Cases missing injury severity were excluded, and all other missing data were imputed. The outcome of interest was Injury Severity Score (ISS) ≥16. The area under the receiver operator characteristic (AUROC) and 95% confidence intervals (CIs) were obtained from 1,000 bootstrapped samples using national case weights. The AUROC for the existing CDC MOI criteria were compared between the 2 decades. The performance of the criteria was also assessed for different age groups based on accuracy, sensitivity, and specificity. Potential new criteria were then evaluated when added to the current CDC MOI criteria.

Results: There were 150,683 (weighted 73,423,189) cases identified for analysis. There was a small but statistically significant improvement in the AUROC of the MOI criteria in the later decade (2010-2019; AUROC = 0.77, 95% CI [0.76-0.78]) compared to the earlier decade (2000-2009; AUROC = 0.75, 95% CI [0.74-0.76]). The accuracy and specificity did not vary with age, but the sensitivity dropped significantly for older adults (0-18 years: 0.62, 19-54 years: 0.59, ≥55 years: 0.37, and ≥65 years: 0.36). The addition of entrapment improved the sensitivity of the existing criteria and was the only potential new criterion to maintain a sensitivity above 0.95.

Conclusions: The MOI criteria for MVCs in the current CDC guidelines still perform well even as vehicle design has changed. However, the sensitivity of these criteria for older adults is much lower than for younger occupants. The addition of entrapment improved sensitivity while maintaining high specificity and could be considered as a potential modification to current MOI criteria.

Keywords: CISS; MVC; NASS; Trauma triage; prehospital.

Figure 1 —

Comparison of ROC analysis for different decades. A: Initial upslope of ROC curve for entire data sets. Points represent performance after adding each criterion B. Probability distribution of AUCs obtained from 1,000 bootstrapped iterations from each decade. [ROC: Receiver Operator Characteristic, AUG: Area Under Curve, Intrusion 12’’ (Occ): Intrusion of 12” at the occupant’s position, Death Comp: Death in the same occupant compartment]

Figure 2 —

Performance of existing CDC criteria for different age groups. Results are median values based on 1,000 bootstrapped samples and error bars represent 95% confidence interval.