In this study, emergency medical services times, along with other crash-related explanatory variables, have been used to investigate influential factors on injury severity. To overcome the complexity of emergency medical services times impact on crash outcome, the interaction effects of EMS times and injury location on the body were also investigated in a separate model. This study utilized the linked data of police-reported crash data and emergency medical services runs, including 2192 crash injuries that transferred to hospital. A random-effects ordered probit approach was implemented to identify effective factors on crash injury severity. Three models of (1) crash-related variables, (2) crash-related and emergency medical services times and (3) crash-related, emergency medical services times and interaction effects of EMS times and injury location on the body were developed. Although the outcome could not find the impact of faster emergency medical services times on injury severity in the second model, in the third model, faster response time and slower on-scene time were associated with decreasing the severity of entire-body injuries. We discuss why this may be the case.

在这项研究中，紧急医疗服务时间，以及其他与撞车相关的解释变量，已被用于调查伤害严重程度的影响因素。为了克服紧急医疗服务时间对撞车结果的影响的复杂性，还使用单独的模型研究了EMS时间和伤害位置对人体的相互作用。这项研究利用了警方报告的碰撞数据和紧急医疗服务运行的链接数据，其中包括2192起转移到医院的碰撞伤害。实施了随机效应有序概率方法来确定影响碰撞伤害严重程度的有效因素。（1）与碰撞相关的变量，（2）与碰撞相关的时间和紧急医疗服务时间以及（3）与碰撞相关的时间，制定了紧急医疗服务时间，以及EMS时间和受伤部位对人体的交互作用。尽管在第二个模型中无法找到更快的紧急医疗服务时间对伤害严重性的影响，但在第三个模型中，更快的响应时间和更慢的现场时间与降低全身性伤害的严重性有关。我们讨论为什么可能会这样。