Temporal Trends and Geographic Associations of Circulatory Disease Hospitalizations Among Young Adults in Almaty and the Turkestan Region, 2018–2024

Background: This study aims to assess temporal trends and geographic differences in hospitalization rates for circulatory system diseases among adults aged 18– 44 years in Almaty and the Turkestan region. Methods: This study analyzed hospitalization data for circulatory diseases (ICD-10 I00–I99) among adults aged 18– 44 years in Almaty, Turkestan city, and rural Turkestan from 2018 to 2024. Crude hospitalization rates per 100,000 population were calculated using official population denominators, and admissions were classified as urgent or planned. The outcome was annual hospitalization counts stratified by year, sex, diagnosis, and geographic location. After detecting overdispersion in Poisson regression, a negative binomial model was applied, providing improved model fit and estimation of incidence rate ratios (IRRs). Results: Hospitalization rates declined substantially through 2022, particularly in Almaty, followed by an increase by 2024. In contrast, the Turkestan region showed more moderate declines, with consistently higher hospitalization rates compared to Almaty. Cerebrovascular and hypertensive diseases were the leading contributors across regions. Urgent admissions accounted for the majority of hospitalizations. Regression analysis demonstrated significant associations with time, age, diagnostic category, and geographic location, with the highest rates observed in rural Turkestan and the lowest in Almaty. No significant sex differences were observed. Conclusion: Hospitalization patterns for circulatory diseases among young adults varied across regions and over time, with a decline observed until 2022 followed by a rebound by 2024. These findings reflect statistically observed associations and should be interpreted cautiously, as they are based on aggregated data and do not establish causal relationships. Keywords: circulatory system diseases, young adults, regional disparities, Kazakhstan, epidemiological trends