Dynamics of emergency medical service calls for acute cerebrovascular incidents: a 15-year analysis of age, gender, and temporal patterns

Objective. To conduct a retrospective analysis of age, gender, and temporal patterns (weekly, seasonal, and annual) in the trends of emergency medical team calls for cerebrovascular accidents over 15 years. The goal was to identify consistent trends critical to resource planning and the optimization of emergency services. Materials and methods. The analysis is based on anonymized data about all hospital-confirmed cases of cerebrovascular accidents (ICD-10 code I64) documented by the emergency medical service in Irkutsk. To mitigate systemic biases and account for the impact of the COVID-19 pandemic, data from 13 years (2007–2019) were reviewed. The data were aggregated, and a standardized incidence rate (per 1.000 person-years) was calculated. The relationship between the number of calls, incidence, and covariates (sex, age groups, and time) was assessed utilizing Poisson regression with robust standard errors. Statistical analyses were conducted using R (version 4.5.0). Results. The analysis revealed a consistent long-term increase in both the absolute number of ambulance calls and the standardized incidence of stroke. The average annual increase in incidence for both sexes among the adult population over the age of 20 was found to be 11% (p<0.001). Notably, the growth rate in men was significantly higher than that observed in women. A pronounced seasonality was observed, with incidence peaks occurring in January and a statistically significant decrease in risk during the summer and autumn months. Weekly patterns showed that Monday had the highest incidence rate, with a consistent decline as the week progressed to Friday. On weekends (Saturday and Sunday), the relative incidence was 24–26% lower than that on Monday. Conclusion. The results from the 13-year analysis indicate a steady increase in stroke cases, with pronounced gender, age, and temporal patterns observed. The identified peaks in workload during the winter months, at the beginning of the week, and the higher utilization of emergency services among males are essential for strategic planning of ambulance service operations.