The diurnal and seasonal relationships of pedestrian injuries secondary to motor vehicles in young people

Introduction There remains a significant morbidity and mortality in young pedestrians hit by motor vehicles, even in the era of pedestrian crossings and speed limits. The aim of this study was to compare the incidence and injury severity of motor vehicle-related pedestrian trauma according to time of day and season in a young population, based on the supposition that injuries would be more prevalent during dusk and dawn and during autumn and winter. Methods Data were retrieved from the National Trauma Audit and Research Network (TARN) database for patients between 10 and 25 years old who had been involved as pedestrians in road traffic collisions between 2013 and 2020. The incidence of injuries, their severity (using the injury severity score (ISS)) and mortality were analysed according to the hours of daylight, darkness and season. Results The study identified a seasonal pattern, highlighting that injuries were most prevalent during autumn (34.9% of injuries). Prevalence decreased throughout the year from winter (25.4%) to spring (21.4%), to summer (18.3%). The greatest incident rate (number of incidents/hour) occurred between 1500–1630 h, correlating to school pick up times, but overall there was no significant difference in injury prevalence between hours of darkness (47.3%) and daylight (52.7%). However, a significant relationship between ISS and daylight hours was demonstrated ( p-value = 0.0124), whereby moderate injuries (ISS score: 9–15) were more likely during the day (72.7%), while severe injuries (ISS score > 15) were more likely at night (55.8%). Conclusion We identified a relationship between the time of day and the frequency and severity of pedestrian trauma in young people. In addition, particular time groupings correspond to the greatest incidents rate, suggesting that reduced visibility coupled with school pick up times play a significant role. We recommend targeted public health measures to improve road safety that focus on these high-risk times of the day.