We all know we are going to die, but how and when it happens depends largely on who we are and where we live. We think we know the major risks - perhaps malaria or AIDS-related diseases in Africa, or stroke, cancer and heart disease in North America and Western Europe. But, in fact, patterns of mortality and morbidity are rapidly changing around the world.
This was the revelation of more than five years of data collection and analysis, which culminated in the recent publication of the Global Burden of Disease Study 2010. Led by the University of Washington’s Institute for Health Metrics and Evaluation (IHME), the study involved 486 authors from 50 countries.
Peter Piot, the director of London’s School of Hygiene and Tropical Medicine, said the speed of change has taken researchers by surprise. “It’s going much faster than I think that we all thought. But there is also enormous diversity.”
Good and bad news
The study reveals that people can expect to live longer - in some cases, dramatically longer. Overall life expectancy worldwide has increased by more than a decade since 1970. The Indian Ocean island nation of Maldives has shown the most striking improvement: a woman there in the 1970s lived on average to 51; now the average lifespan increased by three decades.
But there were also disappointments. The big one, said Chris Murray, IHME’s director, is that health gains have been uneven.
“These rapid transformations in health don’t seem to translate into a change in the leading causes of [disease] burden in sub-Saharan Africa. We have quantified considerable progress there. Child mortality rates are down quite substantially. There’s progress - especially since 2004 - in reducing HIV-related death. There’s progress in reducing malaria due to the scale-up of bed nets and artemisinin-combination therapy. But despite that progress, 65 to 70 percent of the burden of ill-health is still related to MDGs [Millennium Development Goals] four, five and six,” he said, referring to the MDGs to significantly reduce child mortality, improve maternal health, and combat HIV, malaria and other diseases by 2015.
“For me,” Piot told IRIN, “the key is: let’s not assume that the MDGs, as they are now, will all be achieved by 2015, that we can drop that and then move on with a completely blank sheet. That would be a disaster. And that’s what’s in the pipeline, I am sorry to say.”
The researchers noted a shift away from infectious diseases as a cause of death towards non-communicable diseases such as cancer, stroke and heart disease - often called “lifestyle” diseases. Among communicable diseases, only AIDS and, to a lesser extent, malaria have increased since 1990, primarily in sub-Saharan Africa.
Now only 25 percent of deaths globally are due to infectious diseases and maternal, neonatal and nutritional causes. More than 65 percent are due to non-communicable conditions, and just under 10 percent are related to injuries, the bulk of them happening on increasingly deadly roads in the world’s poorest places.
Irene Agyepong, from University of Ghana’s public health school, said countries in Africa are increasingly facing the dual burden of fighting “old” as well as “new” diseases.
“Two years ago, we looked at the data from Greater Accra [the capital area]… which is about 90 percent urban now. And we realized that hypertension had moved to number two among the common causes of outpatient attendance and was a leading cause of death, which is very different from the rest of the country,” she said. “And I was discussing with a colleague that we should start research into cardiovascular disease in low- and middle-income countries, and he was still saying, ‘Why on earth would you do that? It’s not a problem.’”
Data-keeping has surfaced as one of the biggest challenges countries face in setting targets to reduce non-communicable diseases.
Only about two-thirds of the world’s countries have “vital” registration systems that record births and deaths sufficiently to estimate death rates from various causes, according to World Health Organization (WHO). WHO noted in March that 74 countries lacked data on cause of death, while another 81 countries had only lower-quality data.
The IHME-led team said that while researchers have, until now, only occasionally conducted such global disease burden studies, they hope to keep the database updated and freely available. They have also provided a set of interactive tools that present information by different categories, including region and population segment. They plan to add a country filter next year.