In 1990, breast cancer, diabetes, stroke, and other noncommunicable diseases (NCDs) represented roughly a quarter of the total amount of death and disability in poorer nations, as measured in disability-adjusted life-years (DALYs). In 2040, that number is expected to jump to as high as 80 percent in some low-income countries. At that point, the burden of noncommunicable diseases in Bangladesh, Ethiopia, and Myanmar will be roughly the same as it will be in rich nations such as the United States. The difference, of course, is that the same shift from infectious diseases to noncommunicable diseases took roughly three to four times as long in those wealthy nations.
Greater attention is being paid in poorer nations to the role of obesity, tobacco use, air pollution, and other major health risks in the rise of cancers, diabetes, and other noncommunicable diseases. Rightly so. More investment in preventing the adoption of unhealthful habits is critical to slowing the increase of noncommunicable diseases in lower-income countries.
The rise of noncommunicable diseases in lower-income countries is not, however, merely a by-product of worsening diets and unhealthy lifestyles. The figure below is adapted from a recent article in Health Affairs and breaks down the expected contributions of three factors to the overall burden from noncommunicable diseases. Epidemiological change refers to how much death and disability noncommunicable diseases cause for every one thousand people in a region or country income group. Population growth is the expected change in the number of people living in a country. Population aging is the expected change in the median age of the population of a country due to factors such as declining fertility rates or rising life expectancies.
The good news is that the rates of death and disability from noncommunicable diseases are decreasing in every region of the world. These improvements are due to better treatment, improved prevention, or some combination of both. The bad news is that the modest improvement is not keeping pace with the dramatic demographic changes—the population aging and growth— that are occurring in the poorer regions of the world.
The number of adults in poorer countries is increasing rapidly, as is adults’ share of the overall population. In Bangladesh, for example, the median age increased from nineteen to twenty-six years old between 1990 and 2015. Over the same time, its population grew nearly 50 percent. Bangladesh has thirty-eight million more adults between the ages of twenty-five and sixty-four than it did twenty-five years ago. This dramatic demographic change is accelerating the shift in lower-income countries from the infectious, neonatal, and nutritional diseases that disproportionately affect children to the noncommunicable diseases that mostly afflict adults.
The expected pace and scale of the shift in the disease burden to noncommunicable diseases require building different and better funded health-care systems than currently exist in many lower-income nations. Poorer countries have historically focused on acute care for infants, women around the time of childbirth, and infectious diseases such as malaria. Diabetes, most cancers, and cardiovascular diseases are chronic and costly to treat, and require health-care infrastructure and skilled health workers to do so. The government of an average lower-income country spends $23 per person annually on health (adjusting for purchasing power). By contrast, the U.S. government annually spends $3,860 per person on health and the UK government spends $2,695. Most health services and medicines in poorer nations are purchased out of pocket by patients or provided by foreign donors rather than the government. But only 2 percent of overall global health aid goes to address noncommunicable diseases. And almost all of that small amount has been devoted to prevention, not treatment, of noncommunicable diseases.
A recently released Health Affairs index systematically assesses the preparedness of 172 national health systems for the increasing toll of cancers, heart diseases, and other noncommunicable diseases. This index was constructed according to World Health Organization principles for building health systems. It uses data, validated by an independent third party, to assess the availability of the health-care infrastructure and services, skilled health workforce, total health expenditure, and implementation of tobacco control policies as a proxy for prevention. The figure below shows the results.
Countries that are expected to experience the largest increases in death and disability from noncommunicable diseases (the y-axis) are also the least prepared for them (the x-axis). The countries that are facing a potential crisis from noncommunicable diseases are those in the upper right corner of the figure. Health systems of sub-Saharan African nations perform particularly poorly on this index, as do the health systems of a few other lower-income countries (such as Bangladesh and India) that are unprepared for the rise of noncommunicable diseases.
With little access to preventive and primary care, working-age people in lower-income nations are more likely to develop and receive late diagnoses for breast and cervical cancer, hypertension, and other noncommunicable diseases. Without access to chronic care and with limited resources to pay for medical treatment out of pocket, working-age people in those lower-income countries are more likely to become disabled or die at a young age.
Cancers, stroke, diabetes, and other noncommunicable diseases are global problems, but their impact increasingly depends on the wealth of the country in which the patient lives. In rich nations, the increases in death and disability from these diseases are expected to occur mostly among people over the age of seventy, with death and disability decreasing in younger people. The opposite is true in the poorest nations.
In low-income countries, the toll from noncommunicable diseases is expected to surge in all age groups but especially among working-age adults (ages twenty-five to sixty-four years). In lower-middle-income countries, such as Kenya or Vietnam, the increase in death and disability from noncommunicable diseases will be the most dramatic in people older than thirty-five years.
Reductions in obesity, fast-food consumption, and pollution are critically important, but they are not substitutes for a robust and cost-effective health system that can enable poorer nations to respond to the staggering rise in premature death and disability from noncommunicable diseases. More investment and public attention is needed to develop cheaper ways to elevate primary care as the main platform for responding to noncommunicable diseases in the health systems of these lower-income nations. Understanding the speed, scale, and drivers of the shift to noncommunicable diseases at the country level and estimating the preparedness of health systems for that shift is important for the health planning, budgeting, and policy formulation of national governments and donors. The time to act is now.