of the world, giving estimates of morbidity and mortality by age, sex, and region. It also introduced the DALY as a new metric to quantify the burden of diseases, injuries, and risk factors. From 2000 to 2002, the 1990 study was updated to include a more extensive analysis using a framework known as comparative risk factor assessment.

In 2004, the World Health Organization calculated that 1.5 billion disability-adjusted life years