The burden of disease (also called disease burden and global burden of disease) is the total impact of disease on a population.
The concept of burden of disease originates in a study commissioned by the World Bank in 1990 and in collaboration with Harvard University and the World Health Organization (WHO). The study, published in the World Bank's 1993 World Development Report and known as the first Global Burden of Disease study (GBD 1990), was a comprehensive effort to quantify the healthy life years lost globally not only from premature death but also from nonfatal medical conditions. To measure this loss, GBD 1990 introduced the Disability-Adjusted Life Year (DALY), a metric that has since become standard in health impact assessment and informed policy-making. GBD 1990 had considerable influence, both in stimulating other studies focused on various subpopulations and in contributing to the setting of global health priorities.
WHO carried out further GBD studies between 1998 and 2004. Since 2010, GBD studies have been conducted by the Institute for Health Metrics and Evaluation (IHME). The most recent study was completed in 2019.
In 2019, the world population lost 1.68 billion years of life due to premature death—calculated as the sum of the difference between each person's age of death and their life expectancy at that age–and another 863 million years of healthy life, measured in DALYs. This loss corresponds to a burden of 33,073 DALYs per 100,000 people, or about four months of healthy life lost for every person alive. (The global burden of disease per person has been falling consistently for the last three decades. In 1990, when the first study was conducted, it was 48,595 DALYs per 100,000 people.)
Burden of disease figures can be useful not only to assess the current state of the world and make secular comparisons, but also to help with cause prioritization. Different medical conditions, as well as different geographical regions, vary considerably in their contributions to the global burden of disease. An awareness of this variation can significantly assist efforts to allocate resources where they can have the most impact....