Life expectancy is increasing among the world's population, including in the United States, but people are living longer in chronic pain and with physical and mental disabilities, according to findings from the giant Global Burden of Disease study, published Thursday in the journal Lancet.
Seven separate reports conducted by researchers at the University of Washington, the Harvard School of Public Health, and elsewhere gauged people's health in 187 countries and determined that developing countries are looking more like richer Westernized countries in terms of the health problems that pose the biggest burden: high blood pressure, diabetes, cancer, and heart disease.
The new estimates show that, globally, the average life expectancy of males born in 2010 is more than 11 years higher than those born in 1970 -- increasing from 56 years to nearly 68 years. Females born in 2010 had an increased life expectancy of 12 years and can expect to live to more than 73 years of age. Study funding came from the non-profit Bill and Melinda Gates Foundation.
Much of the increase in life expectancy can be attributed to better medical treatments that prolong the lives of cancer and heart disease patients, better control of infectious diseases such as measles, and efforts to improve pediatric health and nutrition. Deaths among children under five years of age declined by nearly 60 percent over the past four decades, with almost 10 million fewer babies and preschoolers dying every year.
At the same time, though, more people are living longer in poorer health, crippled by such maladies as back pain, dementia, depression, and broken hips.
Over the past two decades, overall life expectancy increased by about five years, while the number of years people can expect to spend living in good health increased by about four years.
"For individuals, this is mostly good news," said Joshua Salomon, a professor of global health at Harvard School of Public Health who co-authored four of the studies. "We can expect to live longer, but we also need to expect that we'll be living longer with disabilities and we have to plan for added health care costs."
While welcoming the new studies -- which took five years and 486 researchers from 50 different countries to conduct -- the World Health Organization said in a statement that there's still a pressing need for better data on causes of death from most countries. Researchers rely on statistical models to estimate deaths from various diseases because countries often don't keep such data. "Currently only 34 countries -- representing 15 percent of the world's population -- produce high quality cause-of-death data," the WHO stated, "and almost all of these are in Europe and the Americas."
In another intriguing finding, researchers found striking similarities in how people from various countries -- the United States, Bangladesh, Indonesia, Peru, and Tanzania -- perceived the level of disability caused by a wide range of health conditions, with mental and physical health conditions such as schizophrenia, multiple sclerosis, and severe depression ranking highest in terms of their negative impact on a person's health. Conditions such as hearing loss, vision loss, and infertility were considered among the least disabling.
"We were surprised by finding so few differences," said Salomon, who led the study, "since there's a pretty popular hypothesis that people attach different weights to various health outcomes depending on their culture, wealth, and occupations, which doesn't seem to be the case."
Countries also share common risk factors that contribute to their overall health costs and extent of disease in their populations. From Europe to South America to the Middle East, high blood pressure, excess body fat, a lack of fruits and vegetables in the diet, and smoking all came out on top as the biggest risks leading to poor health -- ahead of air pollution, lead exposure, and drug use.
That follows the same pattern as in the United States, where soaring obesity rates have led to a spike in type 2 diabetes, which often leads to heart disease. New American Heart Association data also published this week noted that the United States spends $313 billion every year to treat heart disease and strokes, compared with $228 billion for cancer treatments.
"Yes, people are living longer with heart disease, but we need to make sure we prolong their years of being free of illness," said epidemiologist Donna Arnett, president of the American Heart Association. "That involves individuals taking matters into their own hands by maintaining a healthy weight, being physically active, avoiding smoking, and following a good diet."