Burden of disease

Aboriginal or Torres Strait Islander: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander. See also Indigenous.

age-standardisation: A set of techniques used to remove, as far as possible, the effects of differences in the age structure when comparing 2 or more populations.

age-standardised rate (ASR): A rate that takes into account the age structure of the population using age-standardisation techniques.

attributable burden: The disease burden attributed to a particular risk factor.

burden of disease (and injury): The quantified impact of a disease or injury on a population using the disability-adjusted life years (DALY) measure.

crude rate: A burden (YLD, YLL or DALY) rate derived from the number of years of healthy life lost recorded in a population during a specified time period divided by the number of people in the population, without adjustments for other factors such as age (see age-standardisation).

disability: In burden of disease analysis, any departure from an ideal health state.

disability-adjusted life years (DALY): A measure of healthy life lost, either through premature death or living with disability due to illness or injury. Often used synonymously with health loss.

disability weight: A factor that reflects the severity of health loss from a particular health state on a scale from 0 (perfect health) to 1 (equivalent to death).

disease: A broad term that can be applied to any health problem, including symptoms, diseases, injuries and certain risk factors, such as high blood cholesterol and obesity. Often used synonymously with condition, disorder or problem.

excess burden: The reduction that would occur in overall disease burden if all groups had the same rate of burden as the least burdened group.

external cause: The environmental event, circumstance or condition that causes injury, poisoning and other adverse effects (for example, road traffic accident).

fatal burden: The burden from dying prematurely as measured by years of life lost. Often used synonymously with years of life lost, and also referred to as ‘life lost’.

health-adjusted life expectancy (HALE): The average number of years that a person at a specific age can expect to live in full health; that is, taking into account years lived in less than full health due to the health consequences of disease and/or injury.

health state: Reflects a combination of signs and symptoms that result in health loss, and are not necessarily unique to one particular disease. A health state might also be a severity level of a sequela (typically mild, moderate and severe levels are distinguished). For example, the health state ‘mild heart failure’ is used as a sequela of coronary heart disease, hypertensive heart disease, congenital heart disease and several other conditions. Each health state is associated with a disability weight.

Indigenous: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander. See also Aboriginal or Torres Strait Islander.

life expectancy: The number of years a person of a particular age can expect to live.

linked disease: A disease or condition on the causal pathway of the risk factor, which is therefore more likely to develop if exposed to the risk.

morbidity: Ill health in an individual, and levels of ill health in a population or group.

mortality: Death.

non-fatal burden: The burden from living with ill-health as measured by years lived with disability. Often used synonymously with years lived with disability.

premature death: Deaths that occur at a younger age than a selected cut-off. In the ABDS, it is defined as dying before the global ideal life span at the age of death. 

rate: A burden (YLD, YLL or DALY) rate is one number (the numerator) divided by another number (the denominator). The numerator is commonly the number of years of healthy life lost in a specified time. The denominator is the population at risk of the event. Rates (crude, age-specific and age-standardised) are generally multiplied by a number such as 1,000 to create whole numbers.

risk factor: Any factor that represents a greater risk of a health condition or health event.

sequelae: Health consequences of diseases and injuries, such as heart failure due to coronary heart disease. Each sequela may be mapped to one or more health states.

total burden: The sum of fatal burden (YLL) and non-fatal burden (YLD), which totals disability-adjusted life years (DALY). See burden of disease (and injury).

years lived with disability (YLD): The number of years of what could have been a healthy life that were instead spent in states of less than full health. YLD represent non-fatal burden.

years of life lost (YLL): The number of years of life lost due to premature death, defined as dying before the ideal life span. YLL represent fatal burden.