Globally, life expectancy increased from about 62 years to nearly 72
from 1980 to 2015, with several nations in sub-Saharan Africa rebounding from high death rates due to HIV/AIDS.
Child deaths are falling fast, as are illnesses related to infectious diseases. But each country has its own specific challenges and improvements, from fewer suicides in France, to lower death rates on Nigerian roadways, to a reduction in asthma-related deaths in Indonesia.
Improvements in sanitation, immunizations, indoor air quality, and nutrition have enabled children in poor countries to live longer over the past 25 years, suggested a new scientific analysis of more than 300 diseases and injuries in 195 countries and territories. However, such progress is threatened by increasing numbers of people suffering serious health challenges related to obesity, high blood sugar, and alcohol and drug abuse.
"Development drives, but does not solely determine health," said Dr. Christopher Murray, Director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle, the coordinating center for the GBD enterprise. "We see countries that have improved far faster than can be explained by income, education, or fertility. And we also continue to see countries - including the United States - that are far less healthy than they should be given their resources."
The report was released at an event co-sponsored by IHME, The Lancet, and the World Bank in Washington, DC. The study was established in 1990 with support from the World Bank. In 2016 researchers analyzed each country using the new Socio-demographic Index metric, examining rates of education, fertility, and income. This new categorization goes beyond the historical classifications of "developed" versus "developing" countries or economic divisions based on income alone.
The six papers provide in-depth analyses of causes of death, maternal mortality, deaths of children under age 5, overall disease burden and life expectancy, years lived with disability, and the risk factors that lead to health loss.
In much of the world, giving birth is safer for mothers and newborns than it has been over the past 25 years. The number of maternal deaths globally dropped by roughly 29% since 1990, and the ratio of maternal deaths fell 30%, from 282 per 100,000 live births in 1990 to 196 in 2015.
However, 24 countries still have what population health experts consider high rates of maternal mortality, more than 400 deaths per 100,000. These include Central African Republic (1,074 deaths per 100,000), Afghanistan (789 per 100,000), and Sierra Leone (696 per 100,000).
Such levels of maternal deaths underscore the need for reproductive health improvements in those three nations and other countries that are far behind the United Nations' goal to have fewer than 70 deaths per 100,000 live births by 2030. Areas for improvement include increased access to family planning, better routine reproductive health care, and improved data collection systems.
The study's other findings include:
- Death rates fell notably between 1990 and 2015. And that trend has been particular strong over the past decade. Between 2005 and 2015, death rates from HIV/AIDS decreased 42%, malaria 43%, preterm birth complications 30%, and maternal disorders 29%.
- Globally, 5.8 million children under age five died in 2015, representing a 52% decline in the number of under-five deaths since 1990. Neonatal deaths fell at a slower pace since 1990, decreasing 42% to 2.6 million; stillbirths declined 47% to 2.1 million.
- Three out of every 10 people globally suffer from tooth decay, while approximately two of every 10 have trouble with tension headaches, anemia, and hearing loss. Other top nonfatal causes of health loss include migraines, vision impairment, genital herpes, and parasitic worms.
- Much of people's health is determined by risk factors, some of which are within one's control. Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each fell more than 25%. However, exposure to several occupational risks, high body mass index, and drug use increased more than 25% over the same period.
"Many nations face significant health challenges despite the benefits of income, education, and low birth rates, while other countries farther behind in terms of development are seeing strong progress," said Dr. Charles Shey Wiysonge, a GBD collaborator from South Africa who serves as a Professor of Clinical Epidemiology at the Faculty of Medicine and Health Sciences, Stellenbosch University, in Cape Town. "Policymakers in all nations - from Afghanistan to Zimbabwe - can use this study to align spending to target the things that will make their communities healthier faster."
Quotes from papers' authors
"In many nations, improvements in maternal health are accelerating, but in others, women face daunting challenges, including the absence of trained professionals to assist with pregnancy and childbirth, and deal with life-threatening emergencies. As a result, reproductive health care must be a higher priority, including the expansion and improvement of reproductive health and family planning services and, for complications in childbirth, more advanced obstetric care."
Dr. Nicholas Kassebaum, Assistant Professor, IHME
Disability-adjusted life years (DALYs)
"The world is seeing a decrease in health loss due to communicable diseases, such as HIV/AIDS, malaria, pneumonia, diarrhea, and measles, but a pernicious rise in non-communicable diseases, especially diabetes, degenerative joints, drug use, and depression. These trends have massive implications for health systems. Without proper preventive care and treatment, these non-communicable diseases will comprise a greater disease burden over the coming years in nations regardless of their rankings on the Socio-demographic Index."
Dr. Nicholas Kassebaum, Assistant Professor, IHME
Mortality and causes of death
"This paper examines the good news that, globally, mortality rates have steadily dropped over the past 25 years. However, our aging populations have led to increasing demands and expectation on health systems. Those responsible for creating, managing, and funding those systems would be well served by using these data, offered free of charge, to address future needs."
Dr. Mohsen Naghavi, Professor of Global Health, IHME
"Over the past 25 years, there have been important and impressive gains in the number of children surviving past their fifth birthdays, a significant milestone. Regrettably, many nations - especially those low on the Socio-demographic Index - have not made such gains and need to hasten the pace of progress, including availability of cost-effective vaccines, expanded access to clean water, and other interventions."
Dr. Haidong Wang, Associate Professor, IHME
Years lived with disability (YLDs)
"Among the more than nine billion estimates of illnesses and injuries we evaluated, non-communicable diseases - or NCDs - account for 18 of the leading 20 causes of years lived in less than ideal health. There are many opportunities to help address most NCDs, such as through prevention, treatment, and rehabilitation. Many of these services are costly and, hence, countries with an aging population are having to spend more on health. For other causes like dementia or low back pain, more research and knowledge are needed to reduce the disease burden as we currently do not have very effective prevention or treatment options for these conditions."
Dr. Theo Vos, Professor of Global Health, IHME