The global burden of neurologic diseases.

WHO categorizes causes of death and disability into (1) communicable diseases, maternal and perinatal conditions, and nutritional deficiencies; (2) non-communicable diseases (NCD); and (3) injuries. NCD are the leading cause of death and disability globally and are rising as a result of demographic and epidemiologic changes occurring in both developed and developing countries.1,2 Increasing life expectancies, unhealthy diet, physical inactivity, tobacco use, and harmful use of alcohol contribute to the growing incidence and prevalence of NCD, such as heart disease, stroke, diabetes, cancers, and chronic respiratory diseases. Deaths from communicable diseases, such as HIV/AIDS, tuberculosis, and malaria, are declining as a result of billions of dollars of annual international and domestic funding that target the prevention and treatment of these diseases. In recent years, less than 3% of official development assistance for health has been directed toward NCD.3 However, when measured in disability-adjusted life-years (DALY), NCD accounted for 54% of the global burden of disease in 2010, compared to 43% in 1990.1 DALY are the sum of 2 components: years of life lost due to premature mortality and years lived with disability. One DALY is the equivalent of one healthy life-year lost (for a complete definition of DALY, see reference 1). DALY are a particularly useful metric to quantify the burden of NCD (e.g., stroke) that often result in long-term disability for survivors.