Injury severity score as a predictor of mortality in adult trauma patients by injury mechanism types in the United States: A retrospective observational study.

Injury severity score (ISS) is commonly used in trauma registries to describe injury severity and to predict outcomes in trauma patients regardless of injury mechanism. This study examined the correlation between ISS and mortality in adult trauma patients presenting to emergency departments in the United States with different mechanisms of injury. A retrospective observational study was conducted using the 2014 Nationwide Emergency Department Sample. Patients' characteristics were stratified by mortality. Receiver operating characteristic (ROC) curves were generated for death against ISS for each mechanism of injury. A logistic regression model was conducted for each mechanism of injury to determine whether ISS (≥16 vs <16) is a predictor of mortality. The study sample consisted of 16,147,058 weighted adult trauma patients. Median age was 46 years. Slightly over half were females (51.9%). Falls, motor vehicle accidents and being struck by or against, were the most commonly reported mechanisms of injury (44.6%, 18.1%, and 15.3%, respectively). The overall mortality in the study population was 0.4%. The area under the ROC curve was highest in injuries sustained in accidents involving machinery (0.947; 95% confidence intervals [CI], 0.896-0.998), followed by motor vehicle traffic (MVA) (0.788; 95% CI, 0.775-0.801) and cutting or piercing (0.746; 95% CI, 0.701-0.791). Deceased patients were accurately identified by ISS 65.2% in injury by machinery, 47.7% in injury involving MVA, 39.7% in injury by firearm and 31.4% in injury by assault. After adjusting for confounders, the multivariate models in which ISS was the main independent factor performed best in predicting mortality from firearm and machinery mechanism of injuries. Although the ROC curve analysis demonstrated a moderate or high discriminatory ability to identify deceased patients in 6 out of twelve mechanisms, and the multivariate analysis revealed that ISS was a significant predictor of mortality in 9 out of 12 injury mechanisms, the sensitivities of all logistic regression models were poor. The ISS ≥ 16 threshold alone therefore should not be used to identify patients with high-mortality risk. The mortality risk assessment should be done individually and be based on clinical evaluation.

Factors Associated with Survival in Adult Trauma Patients Transported to US Trauma Centers by Police.

INTRODUCTION: Police units often reach the trauma scene before Emergency Medical Services (EMS). Initiatives aiming at delivering early basic trauma care by non-medical providers including police personnel are on the rise. This study describes characteristics of trauma patients transported by police to US hospitals and identifies factors associated with survival in this patient population. METHODS: Using the 2015 National Trauma Data Bank (NTDB), an observational study was conducted of adult trauma patients who were transported by police. After describing the study population, the factors associated with survival to hospital discharge were evaluated using a multivariate analysis. RESULTS: A total of 2,394 patients were included in the study. Patients had a median age of 34.0 years (interquartile range [IQR]: 25-48) and most were males (84.5%). Blunt trauma mechanism (59.4%) was more common than penetrating trauma (29.4%). Factors associated with improved survival included: comorbidity (odds ratio [OR] = 2.92; 95% CI, 1.33-6.40); use of drugs (OR = 2.91; 95% CI, 1.07-7.92); cut/pierce (OR = 11.07; 95% CI, 2.10-58.43); motor vehicle traffic (MVT) mechanism (OR = 6.56; 95% CI, 1.60-26.98); trauma resulting in fractures (OR = 3.03; 95% CI, 1.38-6.64); and private/commercial insurance (OR = 3.41; 95% CI, 1.10-10.55). CONCLUSION: In this study population, a relatively high survival rate was noted (93.5%). Police transport of patients with blunt trauma was unexpectedly more common. Factors associated with survival to hospital discharge were identified. These factors can be used to implement more standardized and protocol-driven risk stratification tools of trauma patients on scene to improve police involvement in trauma patient transport.