Global and regional burden of stroke during 1990–2010: findings from the Global Burden of Disease Study 2010

Summary

Background

Although stroke is the second leading cause of death worldwide, no comprehensive and comparable assessment of incidence, prevalence, mortality, disability, and epidemiological trends has been estimated for most regions. We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to estimate the global and regional burden of stroke during 1990–2010.

Methods

We searched Medline, Embase, LILACS, Scopus, PubMed, Science Direct, Global Health Database, the WHO library, and WHO regional databases from 1990 to 2012 to identify relevant studies published between 1990 and 2010. We applied the GBD 2010 analytical technique (DisMod-MR), based on disease-specific, pre-specified associations between incidence, prevalence, and mortality, to calculate regional and country-specific estimates of stroke incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) lost by age group (<75 years, ≥75 years, and in total) and country income level (high-income, and low-income and middle-income) for 1990, 2005, and 2010.

Findings

We included 119 studies (58 from high-income countries and 61 from low-income and middle-income countries). From 1990 to 2010, the age-standardised incidence of stroke significantly decreased by 12% (95% CI 6–17) in high-income countries, and increased by 12% (–3 to 22) in low-income and middle-income countries, albeit non-significantly. Mortality rates decreased significantly in both high income (37%, 31–41) and low-income and middle-income countries (20%, 15–30). In 2010, the absolute numbers of people with first stroke (16·9 million), stroke survivors (33 million), stroke-related deaths (5·9 million), and DALYs lost (102 million) were high and had significantly increased since 1990 (68%, 84%, 26%, and 12% increase, respectively), with most of the burden (68·6% incident strokes, 52·2% prevalent strokes, 70·9% stroke deaths, and 77·7% DALYs lost) in low-income and middle-income countries. In 2010, 5·2 million (31%) strokes were in children (aged <20 years old) and young and middle-aged adults (20–64 years), to which children and young and middle-aged adults from low-income and middle-income countries contributed almost 74 000 (89%) and 4·0 million (78%), respectively, of the burden. Additionally, we noted significant geographical differences of between three and ten times in stroke burden between GBD regions and countries. More than 62% of new strokes, 69·8% of prevalent strokes, 45·5% of deaths from stroke, and 71·7% of DALYs lost because of stroke were in people younger than 75 years.

Interpretation

Although age-standardised rates of stroke mortality have decreased worldwide in the past two decades, the absolute number of people who have a stroke every year, stroke survivors, related deaths, and the overall global burden of stroke (DALYs lost) are great and increasing. Further study is needed to improve understanding of stroke determinants and burden worldwide, and to establish causes of disparities and changes in trends in stroke burden between countries of different income levels.

Funding

Bill & Melinda Gates Foundation.

Introduction

Estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2010) ranked stroke as the second most common cause of death¹ and the third most common cause of disability-adjusted life-years (DALYs)² worldwide in 2010. A previous systematic review³ of population-based studies of stroke incidence from 28 countries showed that incidence is increasing in low-income and middle-income countries, by contrast with high-income countries where a 42% decrease in incidence has taken place in the past four decades. However, no comprehensive and comparable assessment of stroke incidence, prevalence, mortality, disability burden (as measured by DALYs lost), and recent epidemiologic trends has been estimated for most world regions. The GBD 2010 investigators developed statistical methods⁴ to address incomplete epidemiological data and provide the most complete and comparable estimates of the global burden of 291 diseases and injuries in all countries grouped into 21 world regions (appendix). We report estimates from GBD 2010 for stroke incidence, mortality, prevalence, and DALYs lost in all 21 GBD world regions in 1990, 2005, and 2010.