1006. Latest Research on Disease Burden

The term “disease burden” is used to describe the health status of a population. It takes into account the severity and duration of diseases and disabilities, which cannot be grasped by average life expectancy alone. In the 1990s, disability-adjusted life-years (DALYs) were introduced, and this indicator has been used as the basis for the Global Burden of Disease (GBD), the most comprehensive effort to quantify increases and decreases in health worldwide. 

The availability of disease burden estimates facilitates evidence-based interventions as strategies for disease reduction. It also allows progress toward international health goals, such as the SDGs, to be more closely monitored. 

The following briefly explains the terminology used here. Healthy life expectancy (HALE) is the number of years a person can live a healthy life. Years of life lost (YLLs) are the number of years lost from ideal life expectancy due to premature death. Years lived with disability (YLDs) are the number of years spent in impaired or failing health. DALYs=YLDs+YLLs, where DALYs indicate the number of years that deviate from the ideal life expectancy.

Today, we would like to share a paper published in The Lancet on April 17 (GBD 2021 Diseases and Injuries Collaborators, 2024), presenting the latest findings of the GBD 2021 study. It examines not only how the burden of diseases, injuries, and various causes that shorten life expectancy and worsen health outcomes has changed over time, but also how these patterns have differed across countries and regions. For the first time, estimates of health losses due to COVID-19 are also presented.

Global DALYs increased from 2.63 billion in 2010 to 2.88 billion in 2021. Much of the increase was due to population growth and aging, and although there was a downward trend when age was standardized, the global disease burden increased for the first time in 30 years during the two years of COVID-19 (2020 and 2021) even after age standardization. The top three causes of DALYs in 2021 were COVID-19, ischemic heart disease, and neonatal disorders. There was also an increase of 16.4% for depressive disorders and 16.7% for anxiety disorders between 2010 and 2021. In 2021, 31.8% of DALYs were due to YLDs, and the top three causes of YLDs were back pain, depression, and headache disorders. It should be noted that between 2010 and 2021, HALE at birth increased from 61.3 years in 2010 to 62.2 years in 2021.

The increase in DALYs is attributed to (1) the direct impact of the pandemic on health, (2) the indirect impact on health such as mental disorders, and (3) the excessive burden on the health system and inadequate policies. The impact was uneven across age, gender, and location, exacerbating inequalities. Even as global trends in other major communicable diseases, maternal, neonatal, and nutritional diseases (CMNNs) are improving, strengthening prevention and treatment policies and health care systems for currently existing diseases, as well as pandemic preparedness, will continue to be very important.
 

Reference:
GBD 2021 Diseases and Injuries Collaborators. Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021. The Lancet. 17 April 2024. doi: 10.1016/S0140-6736(24)00757-8 (accessed April 22, 2024).

Contributor: SHIRATORI Sakiko (Information and Public Relations Office)