How Pre-Hospital Time Relates to Traffic Injury Severity

Abstract

Background The importance of solid emergency medical response to traffic fatalities has been studied over time, leading for instance to the European Commission action to equipped new vehicles with eCall system. Most studies are however focused on the effect of response time on fatalities resulting from cardiac arrest and fewer from traffic crash consequences. In this context, the present study aims to analyze the effect of the pre-hospital time (dispatch to scene arrival to admission to acute care facility) on the risk of fatalities as well as on the hospital recovery of non-fatal victims. Injury severity was classified according to the maximum abbreviation injury severity. Methods In order to analyze to which extent the pre-hospital time has impact on the probability of dying from a road injury, a binary probit model was used. Additionally, victims' recovery was measured based on the length of hospital stay as well as hospital care costs. These two continuous variables were analyzed considering a generalized lineal model named log link with gamma distribution. For all mentioned models, pre-hospital time was analyzed as an independent variable alongside control variables. The used database corresponds to crash victims occurred in the Porto Metropolitan Area, Portugal, covering a 6-year period. Data from police and hospitals were linked using a mixed deterministic and weight-based probabilistic linkage method. Two databases were created depending on the objectives: one to analyze fatalities (6,608 observations) and other to analyze recovery time and costs, excluding the fatalities, and focused only on patients (467 observations). Results Pre-hospital time variable was significant at the 5% level of confidence in all three models. Results showed that the probability of dying from a crash increased with pre-hospital time. In the same way, when this variable increased, the recovery time and costs increased too. No difference was found between injury severities classified with intermediate scores (i.e. 2 and 3 in a scale of 5). Other control variables such as age and gender of the victim, type of incident and the hospital of assistance showed impacts on the probability of dying and on the recovery process. Conclusions This study shows the relevance of pre-hospital time on injury consequences, adding new value to several studies focused only on the effects on survival. The study results demonstrated that several actions should be applied to improve emergency medical assistance.