Background

Stroke is a leading cause of mortality and disability worldwide and the economic costs of treatment and post-stroke care are substantial. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic, comparable method of quantifying health loss by disease, age, sex, year, and location to provide information to health systems and policymakers on more than 300 causes of disease and injury, including stroke. The results presented here are the estimates of burden due to overall stroke and ischemic and hemorrhagic stroke from GBD 2016.

Methods

We report estimates and corresponding uncertainty intervals (UIs), from 1990 to 2016, for incidence, prevalence, deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs). DALYs were generated by summing YLLs and YLDs. Cause-specific mortality was estimated using an ensemble modeling process with vital registration and verbal autopsy data as inputs. Non-fatal estimates were generated using Bayesian meta-regression incorporating data from registries, scientific literature, administrative records, and surveys. The Socio-demographic Index (SDI), a summary indicator generated using educational attainment, lagged distributed income, and total fertility rate, was used to group countries into quintiles.

Findings

In 2016, there were 5.5 million (95% UI 5.3 to 5.7) deaths and 116.4 million (111.4 to 121.4) DALYs due to stroke. The global age-standardized mortality rate decreased by 36.2% (−39.3 to −33.6) from 1990 to 2016, with decreases in all SDI quintiles. Over the same period, the global age-standardized DALY rate declined by 34.2% (−37.2 to −31.5), also with decreases in all SDI quintiles. There were 13.7 million (12.7 to 14.7) new stroke cases in 2016. Global age-standardized incidence declined by 8.1% (−10.7 to −5.5) from 1990 to 2016 and decreased in all SDI quintiles except the middle SDI group. There were 80.1 million (74.1 to 86.3) prevalent cases of stroke globally in 2016; 41.1 million (38.0 to 44.3) in women and 39.0 million (36.1 to 42.1) in men.

Interpretation

Although age-standardized mortality rates have decreased sharply from 1990 to 2016, the decrease in age-standardized incidence has been less steep, indicating that the burden of stroke is likely to remain high. Planned updates to future GBD iterations include generating separate estimates for subarachnoid hemorrhage and intracerebral hemorrhage, generating estimates of transient ischemic attack, and including atrial fibrillation as a risk factor.