The Stroke Crisis in Ageing Societies: Global Trends, Risk Factors, and Clinical Validation

Background and Objectives: Stroke remains a major global public health challenge, particularly among the elderly population. This study aims to integrate MIMIC-IV clinical data with GBD 2021 data to analyse epidemiological trends and regional differences in stroke among people aged 70 and above, identify key risk factors, and predict future changes in incidence and mortality rates. Methods: The GBD 2021 database provides macro-epidemiological data on global stroke incidence, mortality, prevalence, and disability-adjusted life years (DALYs) from 1990 to 2021, while the MIMIC-IV database provides detailed clinical records for 2,144 stroke patients. Regional differences were assessed using the Socio-Demographic Index (SDI) for stratification. Three core statistical methods were employed: the Estimated Annual Percentage Change (EAPC) to quantify temporal trends in disease indicators, the Bayesian Age-Period-Cohort (BAPC) model to analyse the effects of ageing and predict the disease burden by 2040, and the Multivariate Cox Proportional Hazards Model to assess the impact of clinical risk factors on outcomes. Results: Clinical analysis of 2,144 ICU-treated stroke patients in the MIMIC-IV database revealed significantly higher 28-day mortality in those aged ≥70 years versus younger patients (22.0% vs. 12.7%, p<0.001), driven by heavier comorbidity burdens (hyperlipidaemia: 53.9% vs. 41.8%; diabetes: 36.4% vs. 30.0%) and poorer organ function (SOFA score: 5.0 vs. 4.0, p=0.037). Multivariable Cox regression confirmed age ≥70 years as an independent mortality risk factor (adjusted HR=1.36, 95% CI:1.05-1.76). In parallel, GBD 2021 data showed a 61% global rise in absolute stroke cases (1990-2021), disproportionately affecting Low-middle SDI regions. While High SDI regions achieved declining prevalence (EAPC=−0.53%), Middle SDI regions faced rising rates (EAPC=+0.42%), with East Asia exhibiting the sharpest incidence increase (EAPC=+1.05%). Hypertension dominated global stroke DALYs, followed by high LDL-cholesterol and fasting hyperglycaemia. Projections suggest a continued global decline in incidence and mortality by 2040, albeit at a slowing rate, attributed to accelerating population ageing. Conclusion: Significant regional disparities in the burden of stroke among the elderly are closely related to the level of the SDI and modifiable risk factors. High-SDI regions have reduced the burden of stroke through advanced intervention measures; Low-middle SDI regions urgently need strategic investment.