The Lancet
Global life expectancy has risen by more than six years since
1990 as healthy life expectancy grows; ischemic heart disease, lower
respiratory infections, and stroke cause the most health loss around the world.
People around the world are living longer, even in some of the
poorest countries, but a complex mix of fatal and nonfatal ailments causes a
tremendous amount of health loss, according to a new analysis of all major
diseases and injuries in 188 countries.
Thanks to marked declines in death and illness caused by
HIV/AIDS and malaria in the past decade and significant advances made in
addressing communicable, maternal, neonatal, and nutritional disorders, health
has improved significantly around the world.
Global life expectancy at birth
for both sexes rose by 6.2 years (from 65.3 in 1990 to 71.5 in 2013), while
healthy life expectancy, or HALE, at birth rose by 5.4 years (from 56.9 in 1990
to 62.3 in 2013).
Healthy life expectancy takes into account not just mortality
but also the impact of nonfatal conditions and summarizes years lived with
disability and years lost due to premature mortality. The increase in healthy
life expectancy has not been as dramatic as the growth of life expectancy, and
as a result, people are living more years with illness and disability.
Published in The
Lancet on August 27, the study was conducted by an international
consortium of researchers working on the Global Burden of Disease study and led
by the Institute for Health Metrics and Evaluation (IHME) at the University of
Washington.
"The world has made great progress in health, but now the
challenge is to invest in finding more effective ways of preventing or treating
the major causes of illness and disability," said Professor Theo Vos of
IHME, the study's lead author.
For most countries, changes in healthy life expectancy for males
and females between 1990 and 2013 were significant and positive, but in dozens
of countries including Botswana, Belize, and Syria healthy life expectancy in
2013 was not significantly higher than in 1990.
In some of those countries,
including South Africa, Paraguay, and Belarus, healthy life expectancy has
actually dropped since 1990. People born in Lesotho and Swaziland in 2013 could
expect to live at least 10 fewer years in good health than people born in those
countries two decades earlier.
People in countries such as Nicaragua and
Cambodia have experienced dramatic increases in healthy life expectancy since
1990, 14.7 years and 13.9 years, respectively. The reverse was true for people in
Botswana and Belize, which saw declines of 2 years and 1.3 years, respectively.
The differences between countries with the highest and lowest
healthy life expectancies is stark. In 2013, Lesotho had the lowest, at 42
years, and Japan had the highest globally, at 73.4 years. Even regionally,
there is significant variation. Cambodians and Laotians born in 2013 would have
healthy life expectancies of only 57.5 years and 58.1 years, respectively, but
people born in nearby Thailand and Vietnam could live nearly 67 years in good
health.
As both life expectancy and healthy life expectancy increase,
changes in rates of health loss become increasingly crucial. The study's
researchers use DALYs, or disability-adjusted life years, to compare the health
of different populations and health conditions across time. One DALY equals one
lost year of healthy life and is measured by the sum of years of life lost to
early death and years lived with disability.
The leading global causes of
health loss, as measured by DALYs, in 2013 were ischemic heart disease, lower
respiratory infections, stroke, low back and neck pain, and road injuries.
These causes differed by gender: for males, road injuries were a top-five cause
of health loss, but these were not in the top 10 for females, who lose
substantially more health to depressive disorders than their male counterparts.
Ethiopia is one of several countries that have been rising to
the challenge to ensure that people live lives that are both longer and
healthier. In 1990, Ethiopians could expect to live 40.8 healthy years. But by
2013, the country saw an increase in healthy life expectancy of 13.5 years,
more than double the global average, to 54.3 years.
"Ethiopia has made impressive gains in health over the past
two decades, with significant decreases in rates of diarrheal disease, lower
respiratory infection, and neonatal disorders," said Dr. Tariku Jibat
Beyene of Addis Ababa University. "But ailments such as heart disease,
COPD, and stroke are causing an increasing amount of health loss. We must
remain vigilant in addressing this new reality of Ethiopian health."
The fastest-growing global cause of health loss between 1990 and
2013 was HIV/AIDS, which increased by 341.5%.
But this dramatic rise masks
progress in recent years; since 2005, health loss due to HIV/AIDS has
diminished by 23.9% because of global focus on the disease. Ischemic heart
disease, stroke, low back and neck pain, road injuries, and COPD have also
caused an increasing amount of health loss since 1990.The impact of other
ailments, such as diarrheal diseases, neonatal preterm birth complications, and
lower respiratory infections, has significantly declined.
Across countries, patterns of health loss vary widely. The
countries with the highest rates of DALYs are among the poorest in the world,
and include several in sub-Saharan Africa: Lesotho, Swaziland, Central African
Republic, Guinea-Bissau, and Zimbabwe. Countries with the lowest rates of
health loss include Italy, Spain, Norway, Switzerland, and Israel.
Country-level variation also plays an important role in the
changing disease burden, particularly for non-communicable diseases. For
communicable, maternal, neonatal, and nutritional disorders, global DALY
numbers and age-standardized rates declined between 1990 and 2013. While the
number of DALYs for non-communicable diseases have increased during this
period, age-standardized rates have declined.
The number of DALYs due to communicable, maternal, neonatal, and
nutritional disorders has declined steadily, from 1.19 billion in 1990 to 769.3
million in 2013, while DALYs from non-communicable diseases have increased
steadily, rising from 1.08 billion to 1.43 billion over the same period.
The study also examines the role that socio-demographic status
-- a combination of per capita income, population age, fertility rates, and
years of schooling -- plays in determining health loss.
Researchers' findings
underscore that this accounts for more than half of the differences seen across
countries and over time for certain leading causes of DALYs, including maternal
and neonatal disorders. But the study notes that socio-demographic status is
much less responsible for the variation seen for ailments including
cardiovascular disease and diabetes.
"Factors including income and education have an important
impact on health but don't tell the full story," said IHME Director Dr.
Christopher Murray. "Looking at healthy life expectancy and health loss at
the country level can help guide policies to ensure that people everywhere can
have long and healthy lives no matter where they live."
Countries with highest healthy life expectancy, both sexes, 2013
- Japan
- Singapore
- Andorra
- Iceland
- Cyprus
- Israel
- France
- Italy
- South Korea
- Canada
Countries with lowest healthy life expectancy, both sexes, 2013
- Lesotho
- Swaziland
- Central African Republic
- Guinea-Bissau
- Zimbabwe
- Mozambique
- Afghanistan
- Chad
- South Sudan
- Zambia
Leading causes of DALYs or health loss globally for both sexes,
2013
- Ischemic heart disease
- Lower respiratory infection
- Stroke
- Low back and neck pain
- Road injuries
- Diarrheal diseases
- Chronic obstructive pulmonary disease
- Neonatal preterm birth complications
- HIV/AIDS
- Malaria