Hierarchical Bayesian analysis of prehospital timelines for elderly adults in rural and urban motor-vehicle crashes

• Linked EMS–crash data revealed systematic differences in prehospital timelines for older crash victims. • Hierarchical Bayesian survival modeling jointly quantified response, on-scene, and transport delays. • Longer distances to emergency centers in rural settings were associated with prolonged EMS times. • Older adults experienced consistently longer on-scene times due to assessment and care complexity. • Adverse weather, multi-patient crashes, and off-peak periods further exacerbated EMS delays. Introduction: Emergency medical services (EMS) play a critical role in improving survival after road crashes by providing timely prehospital care. However, differences in EMS response and transport persist between rural and urban areas. Older adults, who make up a large share of rural populations, face additional risks due to frailty and comorbid conditions, yet studies focusing on their prehospital care remain limited. Method: This study analyzed linked EMS and crash data from Ohio (2018–2023) to evaluate prehospital timelines for older adults involved in motor vehicle crashes. Rural–urban classification was determined using Rural–Urban Commuting Area (RUCA) codes. A hierarchical Bayesian survival model was used to assess response, on-scene, and transport times jointly, with predictors including distance to emergency centers, weather, crash characteristics, and time of occurrence. Results: Findings revealed that greater distances to emergency centers, multi-patient crashes, adverse weather, and off-peak or weekend crashes were associated with prolonged EMS timelines. Older adults consistently experienced longer on-scene times, reflecting the added complexity of their assessment and management. Rural areas showed delays, underscoring regional differences in EMS care. Conclusions: These results highlight the need for targeted strategies to improve EMS performance for elderly crash victims, particularly in rural settings. This study offers valuable insights into mitigating variations in EMS availability, highlighting the critical roles of geographic proximity and community-level conditions in shaping emergency response effectiveness. Practical applications: Strategies to reduce gaps should include optimizing EMS base locations, and tailoring prehospital protocols to the needs of older patients. These interventions can improve response efficiency and reduce preventable delays in critical care for elderly crash victims.