Understanding the key correlates of post-crash clinical indicators and outcomes in road traffic crashes

This study investigates the association of pre-crash factors (i.e., driver/rider behaviors and roadway conditions), and emergency response attributes (pre-hospital time (PHT) and mode of evacuation) with clinical outcomes directly and through the three post-crash clinical indicators, harnessing an extensive hospital-based dataset (N = 273,362) collected in Karachi (Pakistan). The three jointly estimated ordered probit models for post-crash clinical indicators including Glasgow Coma Scale (GCS), Systolic Blood Pressure (SBP), and Respiratory Rate (RR) outperformed their independent counterparts, while a multinomial logit model estimated the association of the three post-crash clinical indicators (along with other explanatory variables) with the final clinical outcomes (e.g., mortality, admitted, discharge etc.) in RTCs. The findings reveal that underage driving/riding significantly increases the chance of severe GCS (3-8), RR (<10 bpm), and SBP (<76 mmHg) by 1.959%, 0.957%, and 0.842%, respectively. Delay in pre-hospital time significantly worsens the three post-crash clinical indicators. On the other hand, the chance of severe GCS, SBP, and RR reduced significantly by 6.657%, 5.728%, and 5.528%, respectively, if a private vehicle was used for evacuation. Based on the clinical outcome model, severe GCS, SBP, and RR (compared to their normal values) increase the chance of mortality by 0.444%, 3.149%, and 6.785%, respectively, underscoring RR as the most critical indicator. The findings of path analysis further highlighted indirect effects surpassing direct ones; for example, pre-crash medical conditions of crash victims (mostly drivers/riders) directly increase the chance of mortality by 0.538%; however, in total (after considering indirect effects) by 1.670% via severe post-crash clinical indicators, where the latter is ∼3 times the direct effects. These outcomes underline the significance of effective and well-timed emergency response. Practical implications are discussed in the paper.