*Rationale for use
Substantial resources are devoted to reducing the incidence, duration and
severity of major diseases that cause morbidity but not mortality and to
reducing their impact on people’s lives. It is important to capture both fatal
and non-fatal health outcomes in a summary measure of average levels of
population health. Healthy life expectancy (HALE) at birth adds up expectation
of life for different health states, adjusted for severity distribution making
it sensitive to changes over time or differences between countries in the
severity distribution of health states.
Definition
Average number of years that a person can expect to live in “full health” by
taking into account years lived in less than full health due to disease and/or
injury.
Data sources
Death registration data reported annually to WHO: Mortality data for calculation
of life tables. For countries without such data, available survey and census
sources of information on child and adult mortality are analysed and used to
estimate life tables.
WHO Global Burden of Disease (GBD) study, WHO Multi-Country Survey Study (MCSS)
and World Health Survey (WHS). Estimation of prevalence data. The GBD study
draws on a wide range of data sources to develop internally consistent estimates
for the incidence, prevalence, duration and years lived with disability for 135
major causes. The World Health Survey, carried out by WHO in more than 70
countries, uses anchoring vignettes to maximize comparability of self-report
capacities for a set of core health domains. It also includes a health state
valuation module for assessing the severity of reported health states.
Methods of estimation
Since comparable health state prevalence data are not available for all
countries, a four-stage strategy is used:
Data from the WHOGBD study are used to estimate severity-adjusted prevalence by
age and sex for all countries.
Data from the WHOMCSS and WHS are used to make independent estimates of severity
adjusted prevalence by age and sex for survey countries.
Prevalence for all countries is calculated based on GBD, MCSS and WHS estimates.
Life tables constructed by WHO are used with Sullivan’s method to compute HALE
for countries.
Disaggregation
By age and sex.
References
World Health Report 2004: Changing History. Geneva, World Health Organization,
2004.
Mathers CD, et al. Methods for Measuring Healthy Life Expectancy. In: Murray
CJL, Evans D, eds. Health systems performance assessment: debates, methods and
empiricism. Geneva, World Health Organization, 2003