The main causes of death and disability around the globe have undergone a major shift, with chronic diseases now leading the way, according to a significant new study.
The Global Burden of Disease Study — published as an issue of The Lancet in December — is the result of decades of work to understand the leading causes of death and disability across the globe. The study found that chronic conditions such as heart disease and diabetes are in large part outpacing traditional public health targets such as malnutrition and childhood infectious diseases.
The study tracked 235 causes of death and included both broad data on deaths around the world as well as detailed profiles for health indictors in 187 countries. Researchers spent five years formulating measurements that allowed a comparison between 1990 and 2010. They found heart disease and stroke were the leading and second leading causes of death in both years. But while malnutrition dropped in the rankings from the 11th to the 21st most frequent cause of death in the two-decade period, diabetes, lung cancer and motor vehicle crashes all rose.
The study found life expectancy has improved worldwide, but disability is more prevalent. Mental illness and low back pain are the most common causes of disability, with mental illness responsible for 23 percent of “years lived with disability,” as described in the study, and low back pain linked to 11 percent.
The shift in causes of death and disability does not mean, however, that the world’s funding and attention should shift away from infectious diseases and more toward chronic conditions, the study authors said.
“We still have to be diligent with many of these diseases,” study author Ali Mokdad, PhD, professor of global health at the University of Washington’s Institute for Health Metrics and Evaluation, told The Nation’s Health. “They have a tendency to come back and come back with a vengeance.”
What is needed, Mokdad said, is adequate funding for health systems and support for attention to an array of health woes.
“We shouldn’t take the budget we have and start dividing it,” he said. “We’d end up losing on all fronts.”
Knowing that a health problem exists is not enough to make shifts in funding, study author Theo Vos, PhD, of the University of Queensland in Australia, told The Nation’s Health.
“If you want to do that, you also have to know what a shift in funding would do in terms of health outcomes,” Vos said.
For example, skyrocketing rates of dementia do not warrant huge investments in treatment, because treatment options are few.
“Similarly, if the burden is small, it may be because you’ve been incredibly successful in reducing the amount of ill health,” Vos said. “It might require sustained, ongoing investment, which is likely unless you’ve eradicated a disease, to maintain those levels.”
Mokdad said the rise in chronic illness and inability to adequately provide mental health care can contribute to a “vicious cycle” in which people suffer from a physical condition that contributes to mental problems and they receive inadequate care for both.
“It’s about time for us to combine physical and mental health as one issue that we need to deal with,” Mokdad said. “Unfortunately, in the United States, mental health or mental conditions become an issue when there is an unfortunate event, a shooting somewhere, and then we talk about it. That is what reminds us that we have a problem. In reality, the data tells us that we have a major problem with mental health and we should give it the attention we give other risk factors, such as smoking.”
The study makes a powerful case for public health interventions such as measles vaccination. The childhood disease killed 631,000 people in 1990 and was then the 19th leading cause of death. In 2010, the disease killed 125,000 and was the 62nd leading cause of death.
APHA member Miriam Labbok, MD, MPH, a former chair of the Association’s International Health Section, said the shift toward more death and disability from chronic disease shows the world is aging and makes the case for early interventions such as child nutrition.
“Breastfeeding, for example, has lifelong implications,” Labbok told The Nation’s Health. “Maternity care has lifelong implications for the mother in terms of chronic problems, and so on.”
The study offers the ability to see regional health disparities and ways certain countries are facing what Mokdad called a “dual epidemic” of both chronic and infectious diseases such as HIV/AIDS. Those regional health differences can, in themselves, be a call for action.
For example, homicide is the 27th leading cause of death and disability worldwide but is the leading cause in Central America, Columbia and Mexico and the second leading cause in Brazil and Paraguay. Suicide, the 18th leading cause of death and disability globally, is the fifth in Eastern Europe and sixth in the Asia Pacific region of Brunei, Japan, Singapore and South Korea.
The study is online at www.thelancet.com.
- Copyright The Nation’s Health, American Public Health Association