The Shape of Global Health

• Author: David E. Bloom
• Position: Professor of Economics and Demography in the Harvard School of Public Health.

THE Ebola outbreak has dominated global health news for much of the second half of 2014. This is understandable given the gruesome nature of Ebola virus disease and its lethality, the current absence of a vaccine or cure, and the prospects for Ebola’s rapid and widespread transmission in the presence of weak and slow-to-react local, national, and global health systems—magnified by the prospect of human error.

Ebola also has the potential to impose a heavy economic burden on affected countries and to cause panic and promote political and social instability in already fragile settings. Ebola conjures up comparisons with other killer infectious diseases—like bubonic plague, smallpox, polio, influenza, and HIV.

But notwithstanding past major assaults on, and contemporary threats to, public health, it is important to remember that humanity has made huge achievements in the prevention and management of infectious disease. These advances have been due in large measure to increased access to clean water and sanitation, the development and widespread use of safe and effective vaccines, revolutions in medical diagnosis and treatment, and improvements in nutrition, education, and income. Health systems—the combination of people, formal rules and institutions, informal practices, and other resources that serve the health needs of a population—have also made significant contributions. Especially effective are systems that emphasize disease prevention, aim for universal coverage, and capably conduct surveillance to detect actual and potential threats to public health—promoting better health behaviors and higher health standards and training, retaining, motivating, and enabling health workers.

Health is indisputably a fundamental aspect of well-being, and there are myriad pathways through which its protection and promotion improve human welfare, both for individuals and for societies. Future perils notwithstanding, technological and institutional innovations hold much promise for making the world healthier, wealthier, and more equitable and secure. Health spending is more than a burdensome consumption expenditure, it is an investment in productivity, income growth, and poverty reduction.

Adding years

One of the clearest indications of advances in health is the sharp improvement in how long people live. Over the past six decades, global life expectancy has increased more than 23 years and is projected by the United Nations Population Division to increase almost another 7 years by 2050 (see Chart 1). The chart estimates how long children born in a specified year would be expected to live if they were subject to that year’s age-specific mortality rates for their whole life. The steady increase in life expectancy between 1950 and 2010 reflects a sharp drop in infant and child mortality (the infant mortality rate declined globally from 135 per 1,000 live births in 1950 to 37 in 2010) and longer life spans of adults. Life expectancy hovered around 25 to 30 years throughout most of human history, so recent and projected gains rank among humankind’s greatest achievements.

Nevertheless, the economic and fiscal implications of the improvements in life expectancy, and the meaning of longer lives for human welfare, are unsettled. Researchers present a mixed picture of whether postponing death also postpones the age at which people’s minds and bodies begin to break down and they lose their functional independence.

Although living longer may not always mean living better, life expectancy gains are a hopeful indicator of what is possible in the face of both long-standing and new health threats. These threats include infectious diseases like Ebola, malaria, tuberculosis, HIV, hepatitis, diarrhea, and dengue (including drug-resistant forms of these and other pathogens), as well as chronic infirmities such as cardiovascular disease, cancer, respiratory disease, diabetes, neuro-psychiatric conditions, sense organ disorders, and musculoskeletal disorders.

In 2013, 6.3 million children died before reaching their fifth birthday. That represents a decline from 90 child deaths per thousand live births in 1990 to 46 in 2013. Although this is a major improvement, even this lower level of early childhood deaths highlights a major failing of health systems. Most early childhood deaths can be prevented based on existing knowledge and relatively inexpensive interventions such as vaccination, oral rehydration, improved nutrition, access to contraception, use of insecticide-treated bed nets, improved prenatal care, and reliance on skilled birth attendants. Unintended pregnancies are also an important factor contributing to infant and maternal mortality. Unplanned pregnancies were estimated to account for 40 percent of the 213 million pregnancies that occurred globally in 2012. Thirty-eight percent of these unplanned pregnancies resulted in births, which accounted for a disproportionate share of the roughly 300,000 estimated maternal deaths caused by complications in pregnancy and childbirth.

Noncommunicable diseases

The campaigns that led to the eradication of smallpox and the near-eradication of polio are generally regarded as the most successful public health interventions ever. But the lessons these eradication efforts offer for battling noncommunicable diseases, which account for almost two-thirds of the world’s estimated 53 to 56 million deaths a year, are not altogether clear.

That is because death, or its prevention, is not the only issue in dealing with noncommunicable diseases. A healthful lifestyle is also important. The disability-adjusted life year (DALY) measures the effective years lost to disability and premature death. The table depicts the distribution of deaths and DALYs by cause—globally, and broken down by developed and developing countries. Infectious diseases account for disproportionately more deaths in developing countries, while noncommunicable diseases are relatively more prominent in developed countries. This contrast reflects a phenomenon known as the epidemiological...