Mortality rate of stroke and its determinants in Africa: An umbrella review of systematic review and meta-analysis

Introduction

Stroke is a significant clinical condition characterized by inadequate blood flow to the brain, resulting in cerebral function loss and potential death if not promptly treated. In developed countries, stroke incidence is decreasing due to efforts targeting risk factors like high blood pressure and smoking, though aging populations sustain high overall rates. Globally, stroke ranks among the top causes of death and disability, with Africa experiencing notably high stroke-related mortality rates. Understanding these trends and predictors is crucial for shaping effective healthcare strategies and interventions to reduce stroke mortality across the continent. Therefore, this umbrella review aimed to assess the pooled prevalence of stroke mortality and its associated predictors in Africa.

Method

This umbrella review systematically synthesized findings from systematic reviews and meta-analyses on stroke mortality rates in Africa, following established methodology. Various databases, including PubMed, Embase, Scopus, and others, were searched up to June 2024 for English-language studies reporting stroke mortality prevalence and determinants. Data were extracted using standardized methods in Excel, and study quality was assessed using the AMSTAR tool. Heterogeneity was measured using Higgin's I² Statistics, and summary prevalence estimates were calculated with the Der Simonian-Laird random-effects model. Publication bias was assessed by visually inspecting funnel plots and conducting Egger's regression tests.

Result

In this umbrella review, data from nine systematic review and meta-analysis studies encompassed 341 primary studies with a total sample size of 170,501 stroke patients admitted to hospitals in Africa. The overall pooled prevalence of stroke mortality in Africa was 20.3 % (95 % CI: 17.3–23.2). Western Africa exhibited the highest prevalence at 27 % (95 % CI: 14.4–39.6), and hemorrhagic stroke patients had a notably higher mortality rate of 26.1 % (95 % CI: 24–28.3).

Conclusion

This study reveals significant variations in stroke mortality across Africa, with the highest prevalence reported in Western Africa and among hemorrhagic stroke patients. Factors associated with increased stroke mortality include severe neurological impairment (Glasgow Coma Scale <8), aspiration pneumonia, older age, vascular disease, female gender, lack of aspirin treatment, reduced renal function, and diabetes.