Chart data on this website are derived from the Global Burden of Disease (GBD) study, which is the largest and most comprehensive effort to measure health loss across different places over time. Coordinated by the Institute for Health Metrics and Evaluation (IHME), it draws on the work of more than 7,000 collaborators from 145 countries and territories. The GBD study covers over 360 diseases and injuries, and 85 risk factors.
YLL
YLL stands for years of life lost due to premature deaths. YLLs are calculated by starting with the highest achievable life expectancy in a given year for a given age group, then subtracting the age at which a person in that age group dies.
YLD
YLD stands for years lived with disability. It measures the amount of time people lose to non-fatal diseases and injuries that degrade their health. It is calculated by multiplying a disability’s severity by the time it lasts. This means that a short-term, severe health problem and a long-term, relatively mild health problem could both result in the same number of YLD. YLDs take into account all disabilities, including lower-visibility ones that result in daily pain, lost work time, or an inability for someone to thrive as they otherwise might.
DALY
DALY stands for disability-adjusted life years and is the sum of YLL and YLD. DALY combines premature death and health-related suffering to portray the total years of healthy life lost from all causes. Ranking the causes of DALY in a population shows the health problems that cause the most suffering in a society, either by killing people when they are very young, by shortening lives by a few years, or by causing daily, long-term suffering.
Prevalence
Prevalence is the total number of cases of a disease or injury in a population, or the percentage of people who have the disorder.
Incidence
Incidence is the rate of new cases of a disease or injury in a given time period.
Risk factor
A risk factor is any behavior or condition that increases a person’s likelihood of experiencing a negative health event. That event could be getting an illness, having an accident that causes injury or death, or dying prematurely for any reason. If, over time, people engage in less risky behavior, or if fewer people live in risky conditions, then the incidence of health problems associated with that risk factor should go down.
Socio-Demographic Index (SDI)
The SDI is a measure to determine where a country or other geographic area sits on the spectrum of economic development. Expressed on a scale of 0 to 1, SDI summarizes the averages for income per capita, educational attainment, and birth rates in all areas covered by the GBD study.
Global Burden of Disease Study Results Citation: Institute for Health Metrics and Evaluation (IHME). Findings from the Global Burden of Disease Study. Seattle, WA: IHME. For terms and conditions of use, please visit Terms and Conditions.
