Prevalence Characteristics and Spatial Aggregation of Sudden Cardiac Death in Shandong Province by Counties and Districts, 2020 to 2021.

Background: Sudden cardiac death (SCD) represents a public health concern globally. Given the lack of large-scale comprehensive studies on the epidemiologic features and spatial clustering of SCD in general populations, particularly in the context of cardiovascular and cerebrovascular events in China, this study aims to enrich the evidence base by analyzing its current situation in Shandong Province.

Methods: County-level data from Shandong Province (2020-2021) were used to investigate whether the incidence of SCD varied by age and sex, between urban and rural areas, among different regions, and explored whether a trend toward concentration in its temporal and spatial distribution was evident.

Results: Shandong Province reported a total of 30 458 cases of SCD from 2020 to 2021, peaking in January to April. Most cases occurred in the older population, aged ≥65 years, comprising 78.70% of the total mortality (23 972/30 458). The male/female ratio for the average annual crude and age-standardized mortality rates was 1:0.98 and 1:0.75, respectively, whereas the urban/rural ratio was 1:1.61 and 1:1.40, respectively. Global spatial autocorrelation analysis revealed significant clustering trends of age-standardized mortality rates for both years (Moran of 0.15 and 0.13, respectively, both <0.05). Local spatial autocorrelation analysis identified "high-high" clustering areas of age-standardized mortality primarily in the northwestern cities of Shandong Province: Heze, Liaocheng, and Dezhou.

Conclusions: The mortality of SCD in Shandong Province during 2020 to 2021 demonstrated significant spatial clustering, with higher mortality during winter and spring. Rural older men were identified as a high-risk group. The mortality of SCD increased significantly with age.