The expected value is the predicted indicator value based on the country's per capita income, educational attainment, and total fertility rate.
The observed value is the actual indicator value for the country.
Life expectancy is the number of years that the average member of a group can expect to live. Many things can affect a group’s life expectancy, including things like death rates in children, income, access to health care, diet, and environment. Life expectancy in a group even changes over time as new life-saving technologies emerge, a civil war occurs, or other things happen. Since 1990 life expectancy at birth has increased in most places around the world.
Under-5 mortality is the chance that a child will die before his or her fifth birthday. Health policymakers worldwide have used under-5 mortality as a key indicator of progress in global health and have made the reduction of under-5 mortality a primary goal.
Cause of death
Cause of death estimates show the root causes of deaths within a group, usually expressed as a rate (e.g. deaths per 100,000 population). These are the underlying causes of death, so, for example, if a person dies in a car accident, we attribute their death to the car accident itself and not a particular injury caused by the accident.
YLL stands for years of life lost. It is a measure of premature death within a group of people. 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. Since, for example, achievable life expectancy in 2015 is XX, a person who dies of lung cancer at age 65 will have YY years of life lost.
YLD stands for years lived with disability. It measures the amount of time people lose to diseases and injuries that degrade health but do not cause death. 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 YLDs. For example, someone who needs two months to recover from a car accident but then regains their full health and someone who experiences relatively mild but lifelong back pain could end up losing the same number of years of their lives to disability. 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 stands for disability-adjusted life years. It is the sum of YLLs and YLDs, so DALYs take into account both premature death and health-related suffering to portray the total years of healthy life lost from all causes. Ranking the causes of DALYs in a population shows the health problems that cause the most suffering in a society, whether it is by killing people when they are very young, by shortening by a few years the lives of many people, or by causing daily, long-term suffering for many people.
A risk factor is any modifiable behavior or condition that increases the likelihood that a person will experience 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 that risk factor should go down.
Prevalence is the proportion of people that have a particular illness at a point in time. While incidence captures new cases of a disease, prevalence takes into account people with new and existing cases of a disease. This makes it particularly useful when assessing the impact of chronic diseases. Since chronic diseases last a long time, even a small number of new cases that develop each year can add up over time to many people living with a disease. In that case, prevalence illustrates the many people affected by that disease in a way that incidence does not.