Analysis of the Evolution and Influencing Factors of Emergency Response Times in Megacities: An Empirical Study of Beijing Using Kernel Density Estimation

Background This study examined the distribution, temporal trends, and factors influencing emergency response times (ERT) across Beijing’s functional zones and administrative districts, providing insights for optimizing the city’s emergency response system. Methods Data from 1,2255 million nonemergency ambulance dispatches (2016, 2021, and 2022) were analyzed. Kernel density estimation was used to explore the ERT distribution patterns across Beijing’s functional zones and districts, analyzing variations by year, month, shift, time of day, and disease type. Findings: Ambulance dispatches increased annually. The urban expansion zone had the highest proportion of dispatches (> 45% annually) at the functional zone level. Chaoyang district had the highest share of dispatches (> 15% annually) at the district level, with a decreasing trend. From 2016–2022, ERTs decreased, particularly in the capital functional core zone. However, ERTs increased in Chaoyang and Shunyi in 2022 compared with 2016, whereas Daxing, Xicheng, and Miyun experienced substantial reductions. The proportion of dispatches with ERTs > 2000 s significantly decreased, particularly in the capital functional core zone. At the district level, Xicheng and Daxing presented the greatest reductions in ERTs > 2000 s. Daytime shifts dominated citywide dispatches of ambulances > 2000 s; however, their proportions decreased in Chaoyang, Tongzhou, Mentougou, Miyun, and Pinggu. Dispatch analysis at > 2000 s revealed increased respiratory and circulatory system diseases, whereas the proportions of neurological, pain-related, and infectious diseases decreased. Interpretation: ERTs in Beijing improved significantly between 2016 and 2022, especially in the capital functional core zone and Xicheng. Daxing’s consistently low ERTs serve as models for improving response times.