Predictors of Outcomes of Pedestrian Casualties in Motor Vehicle Injuries Managed in Emergency Department

Abstract

Introduction Pedestrian injury is a major health care concern. This study aims to identify predictors of mortality and severe injury in pedestrian casualties in motor vehicle injury managed in emergency department in the local setting. Methods This is a retrospective cohort study of a linked hospital and police trauma registry (2004 to 2008). All pedestrian casualties treated in the emergency department (ED) of two regional hospitals in Hong Kong were included. Logistic regression was performed for potential predictor variables (age >65 years; injury patterns including head or face, thorax/abdomen/pelvis, neck/spine, extremities; existence of multiple injuries; heavy vehicles involved; body impact with the vehicles; injury at night and wet road surface) against mortality and severe injury, defined as Injury Severity Scale (ISS) >15. Results A total of 1542 pedestrian casualties were analysed. Age >65 was found to be an independent predictor of mortality in pedestrian casualties, with odds ratio (OR) of 5.15 (95% CI=2.21-12.00; p<0.001). Other independent predictors of mortality included injury to head/face (OR=4.52, 95% CI=1.75-11.7, p=0.002), injury to thorax/abdomen/pelvis (OR=13.36, 95% CI=5.64-31.6; p<0.001), multiple injuries (OR=4.0, 95% CI=1.06-15.1; p=0.041) and wet road surface (OR=3.27, 95% CI=1.31-8.17; p=0.011). These factors were also independent predictors for severe injury. Involvement of heavy vehicles and body impact with vehicles were not independent predictors of mortality. However, these were significant predictors of severe injury (OR=1.86 and 2.85 respectively). Conclusion Old age, injury to head/face or thorax/abdomen/pelvis, multiple injuries and wet road surface in accident scene are independent predictors for mortality in pedestrian casualties. In addition, involvement of heavy vehicles and body impact with vehicles are predictors of severe injury.