Concept Architecture
Concept
Theoretically, Healthy Life Expectancy (HALE) Calculation is a summary population health measure that estimates the average number of years an individual is expected to live in full health by adjusting total life expectancy for time spent in states of less than full health. Developed within burden of disease methodology, HALE combines mortality and non-fatal health outcomes into a single metric that reflects both longevity and health status. It exists to quantify healthy survival and facilitate comparisons of population health across countries, regions and time.
Mathematically, HALE is calculated by weighting the person-years lived within each age interval of a life table by the average health state utility or disability weight applicable to that interval. The health-adjusted person-years are accumulated across all remaining ages and divided by the number of survivors at the starting age. Modern HALE estimates, such as those produced by the Global Burden of Disease Study, are derived using Sullivan-type life table methods combined with age-specific disability weights.
In practice, HALE is estimated using national life tables together with epidemiological data on disease prevalence and disability weights. International organisations, including the World Health Organization and the Global Burden of Disease Study, routinely calculate HALE to monitor population health, evaluate trends in healthy ageing and support health policy, priority setting and international comparisons.
Purpose
Used to estimate expected years of life in full health, assess population health, compare health outcomes across populations, monitor healthy ageing and inform health policy, burden of disease analyses and resource allocation.
Mathematical Formulae
Primary Formula
HALE? = (????? L?(1 ? DW?)) / l?
where:
- HALE? = healthy life expectancy at age x
- L? = person-years lived in age interval i
- DW? = average disability weight for age interval i
- l? = number of survivors at age x
- ? = final age interval
Supporting Formulae
Health-adjusted person-years:
HPY? = L?(1 ? DW?)
Years lived in less than full health:
YUH? = LE? ? HALE?
where:
- LE? = life expectancy at age x
Related Mathematical Methods
- Sullivan method
- Life table analysis
- Burden of disease modelling
- Disability weighting
- Health expectancy estimation
Example
A life table shows that individuals aged 65 accumulate 2,100,000 remaining person-years. After adjustment using age-specific disability weights, the total healthy person-years equal 1,850,000. If 100,000 individuals survive to age 65:
HALE?? = 1,850,000 / 100,000 = 18.5 years
An individual aged 65 is therefore expected to live an average of 18.5 years in full health.
Excel Implementation
| Function | Example Formula | Health Economics Application |
|---|---|---|
| PRODUCT | =B2*(1-C2) | Calculates health-adjusted person-years for each age interval. |
| SUM | =SUM(D2:D20) | Totals health-adjusted person-years across remaining age intervals. |
/ | =SUM(D2:D20)/B1 | Calculates HALE by dividing cumulative healthy person-years by survivors at the starting age. |
| SUMPRODUCT | =SUMPRODUCT(B2:B20,1-C2:C20) | Calculates total healthy person-years directly from life table and disability weight data. |
VBA (Optional)
Automate HALE estimation by integrating life table data with disability weights and producing standardised health expectancy reports.
Sources
- World Health Organization. WHO Methods and Data Sources for Healthy Life Expectancy (HALE).
- Murray CJL, Salomon JA, Mathers CD, Lopez AD. Summary Measures of Population Health: Concepts, Ethics, Measurement and Applications. World Health Organization.
- Murray CJL, Lopez AD. The Global Burden of Disease. Harvard School of Public Health.
- Drummond MF, Sculpher MJ, Claxton K, Stoddart GL, Torrance GW. Methods for the Economic Evaluation of Health Care Programmes. Oxford University Press.
- NICE. Health Technology Evaluation Manual.
Related Concepts (2)
Library
Publications
1
NICE DSU Technical Support Document 8: An Introduction to the Measurement and Valuation of Health for NICE Submissions — Brazier, Rowen, TSD 8 ed., 2011 (NICE Decision Support Unit (University of Sheffield))
An introduction to the measurement and valuation of health for NICE submissions — the QALY, health-state utility values, generic preference-based measures, and the requirements of the NICE reference case.
Frequently Asked Questions (6)
What is HALE calculation?
The process of computing health-adjusted life expectancy, combining mortality data with health state prevalence and severity weights into one summary measure.
Source: Robine & Ritchie 1991
What does HALE calculation compute?
Health-adjusted life expectancy calculation computes a summary measure of population health by combining mortality data with the prevalence and severity of health states, weighting years of life by the health experienced during them. Rather than counting all years equally, as life expectancy does, it discounts years lived in less than full health according to their severity, giving the equivalent years of full health a person can expect. The result expresses length of life adjusted for its quality.
Source: Robine & Ritchie 1991
What inputs does HALE calculation require?
The calculation requires age-specific mortality, from which a life table is built, and age-specific data on the prevalence of health states together with severity weights that value each state on a scale from full health to death. The years lived at each age are weighted by the average health at that age, and the weighted years are summed. It therefore needs both survival data and valuations of the health states the population experiences.
Source: Robine & Ritchie 1991
How does the Sullivan method apply to HALE?
The Sullivan method computes health-adjusted life expectancy by taking the years of life lived at each age from a standard life table and weighting them by the average health-state value at that age, drawn from cross-sectional prevalence and severity data. Summing the weighted years and dividing by survivors gives the health-adjusted life expectancy from a given age. It requires only a life table and health-state data, which makes it the common approach.
Source: Robine & Ritchie 1991
How does HALE differ from disability-free life expectancy?
Disability-free life expectancy divides years into those with and without disability and counts only the disability-free ones, treating health as present or absent, whereas health-adjusted life expectancy weights every year by the severity of the health experienced, on a graded scale. HALE therefore captures gradations of health that a simple disability-free measure does not, giving each year a value between zero and one rather than counting it fully or not at all.
Source: Robine & Ritchie 1991
How is HALE used?
Health-adjusted life expectancy is used to summarise and compare population health, combining how long people live with how healthy those years are, and to monitor whether gains in longevity are matched by gains in healthy years. It is reported by international bodies to compare countries and track change over time, and it informs debate about the compression or expansion of morbidity. It provides a single measure integrating mortality and morbidity.
Source: Robine & Ritchie 1991
Trust Record
Verified by Dr Darrin Baines
British health economist
Professional identity: darrinbaines.org
Verification date: 29 Aug 2025
Content version: 1.0.0
Canonical Identity
- Persistent URI
- https://healtheconomics.wiki/concept/hale-calculation
- Term code
- HE-EE-HU-029
Stable URI · Machine-readable · Resolvable · CC BY 4.0