Number of strokes, related deaths increased significantly in past 3 decades

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.

“We wanted to provide an update on the burden of stroke on the global, regional and national levels from 1990 to 2019,” Valery L. Feigin, MD, PhD, FAAN, FRSNZ, FRAS, of the National Institute for Stroke and Applied Neurosciences at Auckland University of Technology in New Zealand, told Healio Neurology. “For the majority of countries, our Global Burden of Diseases, Injuries and Risk Factors (GBD) Study data are the only reliable estimates of stroke burden in those countries.

“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,” Feigin added.

Feigin and colleagues 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%.

Feigin and colleagues 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.

According to Feigin, 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,” Feigin 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, Feigin 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, Feigin 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,” Feigin said.

In a related editorial, Jeyaraj Durai Pandian, of the department of neurology at the Christian Medical College and Hospital in India, and Ivy Anne Sebastian, of the department of neurology at St. Stephen’s Hospital in India, emphasized the importance of outlining key factors along the continuum of stroke care.

“Stroke is a preventable, treatable and manageable disease,” Pandian and Sebastian wrote. “The challenge is to discern which fundamental elements across the continuum of stroke care can be improved cost-effectively to maximize benefit. Implementing an integrated approach toward evidence-driven policy making, with active collaboration with the health-care policy makers, stakeholders and government agencies, is the path to diminishing the inequalities in stroke prevention and care across the world.”