Healthy life expectancy (HALE) summarises mortality and non-fatal outcomes in a single
measure of average population health. It has been used to compare health between countries,
or to measure changes over time. These comparisons can inform policy questions that
depend on how morbidity changes as mortality decreases. We characterise current HALE
and changes over the past two decades in 187 countries.
Using inputs from the Global Burden of Disease Study (GBD) 2010, we assessed HALE
for 1990 and 2010. We calculated HALE with life table methods, incorporating estimates
of average health over each age interval. Inputs from GBD 2010 included age-specific
information for mortality rates and prevalence of 1160 sequelae, and disability weights
associated with 220 distinct health states relating to these sequelae. We computed
estimates of average overall health for each age group, adjusting for comorbidity
with a Monte Carlo simulation method to capture how multiple morbidities can combine
in an individual. We incorporated these estimates in the life table by the Sullivan
method to produce HALE estimates for each population defined by sex, country, and
year. We estimated the contributions of changes in child mortality, adult mortality,
and disability to overall change in population health between 1990 and 2010.
In 2010, global male HALE at birth was 58·3 years (uncertainty interval 56·7-59·8)
and global female HALE at birth was 61·8 years (60·1-63·4). HALE increased more slowly
than did life expectancy over the past 20 years, with each 1-year increase in life
expectancy at birth associated with a 0·8-year increase in HALE. Across countries
in 2010, male HALE at birth ranged from 27·9 years (17·3-36·5) in Haiti, to 68·8 years
(67·0-70·4) in Japan. Female HALE at birth ranged from 37·1 years (26·9-43·7) in Haiti,
to 71·7 years (69·7-73·4) in Japan. Between 1990 and 2010, male HALE increased by
5 years or more in 42 countries compared with 37 countries for female HALE, while
male HALE decreased in 21 countries and 11 for female HALE. Between countries and
over time, life expectancy was strongly and positively related to number of years
lost to disability. This relation was consistent between sexes, in cross-sectional
and longitudinal analysis, and when assessed at birth, or at age 50 years. Changes
in disability had small effects on changes in HALE compared with changes in mortality.
HALE differs substantially between countries. As life expectancy has increased, the
number of healthy years lost to disability has also increased in most countries, consistent
with the expansion of morbidity hypothesis, which has implications for health planning
and health-care expenditure. Compared with substantial progress in reduction of mortality
over the past two decades, relatively little progress has been made in reduction of
the overall effect of non-fatal disease and injury on population health. HALE is an
attractive indicator for monitoring health post-2015.
The Bill & Melinda Gates Foundation.
Copyright © 2012 Elsevier Ltd. All rights reserved.