Number of strokes, related deaths increased significantly in
Annual strokes and related deaths increased significantly between 1990 and 2019, despite significant reductions in age-standardized rates, according to a systematic analysis published in The Lancet Neurology.

“Until now, there were no accurate estimates of the burden of intracerebral hemorrhage and subarachnoid hemorrhage presented separately, nor were there accurate estimates of the global, regional and national burden of ischemic stroke, intracerebral hemorrhage and subarachnoid hemorrhage attributable to various risk factors,” researchers added.

Researchers used GBD 2019 analytical tools to determine stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs) and the population attributable fraction of DALYs linked to 19 risk factors for 204 countries and territories between 1990 and 2019. They calculated estimates for ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage and all strokes combined, with stratifications for sex, age group and World Bank country income level.

Results showed 12.2 million incident cases of stroke, 101 million prevalent cases of stroke, 143 million DALYs linked to stroke and 6.55 million deaths from stroke in 2019. Stroke accounted for 11.6% of global deaths and 5.7% of total DALYs, making it the second-leading cause of death and the third-leading cause of death and disability combined in 2019. The researchers noted increases of 70% in the absolute number of incident strokes, 85% in prevalent strokes, 43% in deaths from stroke and 32% in DALYs linked to stroke between 1990 and 2019. However, they reported decreases of 17% in age-standardized stroke incidence, 36% in mortality, 6% in prevalence and 36% in DALYs during this period. Among those younger than 70 years, prevalence rates increased by 22% and incidence rates by 15%.

Researchers reported a 3.6-fold higher age-standardized stroke-related mortality rate among the World Bank low-income group vs. the World Bank high-income group, as well as a 3.7-fold higher age-standardized stroke-related DALY rates among the low-income group vs. the high-income group in 2019. Ischemic stroke accounted for 62.4% of all incident strokes in 2019, intracerebral hemorrhage 27.9% and subarachnoid hemorrhage 9.7% in 2019.

High systolic BP, high BMI, high fasting plasma glucose, ambient particulate matter pollution and smoking were the five leading stroke risk factors in 2019. These results relate to clinical relevance in several ways.

“The burden of stroke is increasing/changing fast, and it is of crucial importance for health care decision makers to have the most up-to-date data on stroke burden (including three major pathological types of stroke presented in the paper) for evidence-based health care planning and resource allocation,” researchers said. “For example, they can now estimate the number of hospital beds and staff required for acute stroke care, including neurosurgical beds and staff, the number of rehabilitation staff required in the community for stroke survivors, etc.”

Further, population attributable risks linked to stroke burden can help health care policy makers determine stroke prevention priorities on the global, regional and national levels. For example, they noted that in countries where obesity is shown to be one of the leading risk factors, more emphasis should be placed on measures to improve the population’s diet and physical activity, whereas in countries where air pollution is shown to be one of the leading risk factors, efforts should focus on its reduction.

Lastly, researchers said these findings can inform the assessment of the effectiveness of measures undertaken for primary stroke prevention.

“For example, by comparing the trend in stroke burden and population-attributable risks, health care policy makers can assess the effectiveness of their efforts (if any) to reduce stroke burden,” they said.