In this cluster, we define the outcomes that matter to health and social care, including ‘Amenable mortality’, ‘Healthy life-expectancy’, ‘Quality-adjusted life-year’ or QALY, ‘Disability-adjusted life-year’ or DALY, ‘Potential years of life lost’ and ‘Years lived with a disability’.

Amenable mortality

… the concept of “amenable mortality,” referring to deaths from certain causes that should not occur in the presence of timely and effective health care.

Source: Nolte E, McKee CM (2008) Measuring The Health Of Nations: Updating An Earlier Analysis. Health Affairs 2008; 27(1): 58-71.

Example of the term in use:

Differences between males and females are much higher in countries with high amenable mortality rates than in countries with low amenable mortality rates, indicating that the well-known gap between male and female premature mortality is partly amenable to healthcare.

Gay JG, Paris V, Devaux M, de Looper M (2011) Mortality Amenable to Health Care in 31 OECD Countries: Estimates and Methodological Issues. OECD Health Working Papers No. 55. DOI:

Healthy life-expectancy

The average number of years that an individual is expected to live in a state of self-assessed good or very good health, based on current mortality rates and prevalence of good or very good health.

Source: Public Health England. Health Profile for England: 2017. Chapter 1: life expectancy and healthy life expectancy. Published 13 July 2017.

Example of the term in use:

  • Healthy life expectancy (HLE) at birth for males was 63.1 years and for females was 63.7 years in 2014 to 2016.

  • Females continue to live more years in good health than males, despite their HLE decreasing by 1.7 months since 2009 to 2011 and that of males increasing by 4.3 months over the same period.

Office for National Statistics. Health state life expectancies, UK: 2014 to 2016. Reporting the variations in the self-assess general health and activity limitation among local areas in the UK during 2014 to 2016. Release date: 7 December 2017.

Quality-adjusted life year – QALY

A measure of the state of health of a person or group in which the benefits, in terms of length of life, are adjusted to reflect the quality of life. One QALY is equal to 1 year of life in perfect health.

QALYs are calculated by estimating the years of life remaining for a patient following a particular treatment or intervention and weighting each year with a quality-of-life score (on a 0 to 1 scale). It is often measured in terms of the person’s ability to carry out the activities of daily life, and freedom from pain and mental disturbance.

Source: NICE (2018) Glossary.

Example of the term in use:

In assessing clinical and cost-effectiveness, comparisons can be made between costs per QALY for different medicines. Some medicines may have a low cost per QALY and we would say these offer good value for money. Medicines with a high cost per QALY would not be considered good value for money. In the UK, a cost per QALY of under £20,000 is generally considered acceptable value for money by health technology assessment organisations.

Scottish Medicines Consortium and NHS Scotland (undated) A guide to Quality Adjusted Life Years (QALYs).

Disability-adjusted life year – DALY

One DALY can be thought of as one lost year of “healthy” life. The sum of these DALYs across the population, or the burden of disease, can be thought of as a measurement of the gap between current health status and an ideal health situation where the entire population lives to an advanced age, free of disease and disability.

DALYs for a disease or health condition are calculated as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences:


The YLL basically correspond to the number of deaths multiplied by the standard life expectancy at the age at which death occurs. The basic formula for YLL (without yet including other social preferences discussed below), is the following for a given cause, age and sex:

YLL = N x L


N = number of deaths

L = standard life expectancy at age of death in years

Source: World Health Organization (2018) Health statistics and information systems. Metrics: Disability-Adjusted Life Year (DALY). Quantifying the Burden of Disease from mortality and morbidity.

Example of the term in use:

The proportion of total DALYs borne by children under 15 years old globally declined from 47% in 2000 to 32% in 2016, reflecting the massive reduction in deaths among children under 5 years old during this period. Almost all (87%) of DALYs borne by children under 15 years old, however, were caused by premature death, the remaining 13% were caused by ill health and disability.

World Health Organization (2018) Global Health Observatory (GHO) data. Disability-adjusted life years (DALYs).

Potential years of life lost

Potential years of life lost (PYLL) is a summary measure of premature mortality which provides an explicit way of weighting deaths occurring at younger ages, which are, a priori, preventable.

The calculation for PYLL involves adding up deaths occurring at each age and multiplying this with the number of remaining years to live until a selected age limit.

Source: Organisation for Economic Co-operation and Development. Glossary of Statistical Terms. Potential Years of Life Lost.

Example of the term in use:

Excess bodyweight was positively associated with risk factors for cardiovascular disease and type 2 diabetes. The effect of excess weight on years of life lost was greatest for young individuals and decreased with increasing age.

Grover SA, Kaouache M, Rempel P et al (2014) Years of life lost and healthy life-years lost from diabetes and cardiovascular disease in overweight and obese people: a modelling study. BMJ Diabetes & Endocrinology 3(2): 114-122.

Years lived with disability (YLDs)

Years lived with disability: computed as the prevalence of different disease sequelae and injury sequelae multiplied by disability weights for that sequela. Disability weights are selected on the basis of surveys of the general population about the health loss associated with the health state related to the disease sequela.

Source: US Burden of Disease Collaborators. The state of US health, 1990-2010: burden of disease, injuries, and risk factors. JAMA 2013; 310(6): 591-608.

Example of the term in use:

For YLDs, women had higher rates of disability for all the ten leading conditions than did men, except for sense organ diseases, falls and drug use disorders.

Steel N, Ford JA, Newton JN et al (2018) Changes in health in the countries of the UK and 150 English Local Authority areas 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet 2018; 392: 1647-61. Published Online October 24, 2018.