VIII. Health and Longevity

The health of a country’s population is often monitored using two statistical indicators: life expectancy at birth and the under-5 mortality rate. These indicators are also often cited among broader measures of a population’s quality of life because they indirectly reflect many aspects of people’s welfare, including their levels of income and nutrition, the quality of their environment, and their access to health care, safe water, and sanitation.

Life expectancy at birth indicates the number of years a newborn baby would live if health conditions prevailing at the time of its birth were to stay the same throughout its life. This indicator does not predict how long a baby will actually live, but rather reflects the overall health conditions characteristic of this particular country in this particular year. The under-5 mortality rate indicates the number of newborn babies who are likely to die before reaching age 5 per 1,000 live births. Because infants and children are most vulnerable to malnutrition and poor hygienic living conditions, they account for the largest portion of deaths in most developing countries. Therefore, decreasing under-5 mortality is usually seen as the most effective way of increasing life expectancy at birth in the developing world.

Global Trends

During the second half of the 20th century health conditions around the world improved more than in all previous human history. Average life expectancy at birth in low- and middle-income countries increased from 40 years in 1950 to 65 years in 1998. Over the same period the average under-5 mortality rate for this group of countries fell from 280 to 79 per 1,000. But these achievements are still considerably below those in high-income countries, where average life expectancy at birth is 78 years and the average under-5 mortality rate is 6 per 1,000.

Throughout the 20th century, national indicators of life expectancy were closely associated with GNP per capita. If you compare Figure 8.1 (Life expectancy at birth, 1998) with Figure 2.1 (GNP per capita, 1999), you will find that in general the higher a country’s income per capita, the higher is its life expectancy—although this relationship does not explain all the differences among regions and countries. (See Data Table 1 and Data Table 3 for country-specific data.) The two other factors believed to be the most important for increasing national and regional life expectancies are improvements in medical technology (with some countries clearly making better use of it than others) and development of and better access to public health services (particularly clean water, sanitation, and food safety control). Education, especially of girls and women, makes a big difference too, because wives and mothers who are knowledgeable about healthier lifestyles play a crucial role in reducing risks to their families’ health.

These other factors help explain how most developing countries are catching up with developed countries in terms of people’s health even though they are generally not catching up in terms of per capita income (see Chapter 4). Progress in medical technology, public health services, and education allows countries to realize “more health” for a given income than before. For example, in 1900 life expectancy in the United States was about 49 years and income per capita was more than $4,000. In today’s Sub-Saharan Africa life expectancy is about 50 years even though GNP per capita is still less than $500.

In general, for nearly all countries, life expectancy at birth continued to grow in recent years (see Data Table 3). In developing countries this growth was largely due to much lower under-5 mortality (see Figure 8.2). Better control of communicable diseases that are particularly dangerous for children, such as diarrhea and worm infections, accounts for most of the gains. In many countries higher per capita incomes (see Chapter 4 and Data Table 1) also contributed to better nutrition and housing for most families.

Governments of developing countries have invested in improving public health measures (safe drinking water, sanitation, mass immunizations), training medical personnel, and building clinics and hospitals. But much remains to be done. The average level of public health expenditures in low-income countries is still only 1 percent of GDP compared with 6 percent in high-income countries. Malnutrition, especially among women and children, is still a big problem (see Chapter 6). Communicable, largely preventable diseases still claim millions of lives (see below in this chapter). And little progress has been made in reducing maternal mortality rates. Over half a million women die every year in pregnancy or childbirth, most often in low-income countries (see Data Table 3). The main reasons are low access of poor women to trained health personnel and emergency care combined with high fertility rates. Whereas in Europe 1 in 2,400 women dies in pregnancy or childbirth, in Africa this figure is as high as 1 in every 20 women. Initiatives aimed at helping women prevent unwanted pregnancies and at getting personnel trained in midwifery to attend all deliveries could make a big difference.

In those countries where the total burden of disease has declined, the structure of disease has shifted from a preponderance of communicable disease (diarrhea, worm infections, measles) to a preponderance of non-communicable disease (heart and circulatory disease, cancer). However, this shift is particularly obvious in industrialized countries (including European transitional countries), while in developing countries infectious diseases are responsible on average for almost half of mortality.

Population Age Structures

The health and the longevity of a country’s people are reflected in its population age structure—that is, the percentages of total population in different age groups. A population age structure can be illustrated using a “population pyramid,” also known as an age-sex pyramid. In such pyramids a country’s population is divided into males and females as well as age groups (for example, five-year age groups, as in Figure 8.3). Figure 8.3 shows population pyramids typical of low- and high-income countries in 1995 and those expected to be typical in 2025 if current population trends continue. Note how these shapes represent higher birth rates, higher death rates (particularly among children), and lower life expectancies in low-income countries. Think about why in poor countries the base of the pyramid is broader and the pyramid is basically triangular rather than pear-shaped or rectangular as in rich countries. Explain also the changes expected to happen to both pyramids by 2025.

As seen in Figure 8.3, in low-income countries more than one-third of the population is under 15, compared with less than one-fifth in high-income countries. From a social and economic perspective, a high percentage of children in a population means that a large portion is too young to work and, in the short run, is dependent on those who do. This is the main reason for the relatively high age dependency ratio in most developing countries. While in high-income countries there are roughly 2 people of working age to support each person who is too young or too old to work, in low-income countries this number is around 1.0–1.5. The good news is that declining fertility in developing countries (see Chapter 3) is expected to result in declining dependency ratios for the next few decades, before the enormous army of today’s and tomorrow’s young workers become too old to work, and dependency ratios rise again. Experts point out that this opens a “window of opportunity” for developing countries to spend relatively less on supporting the nonworking, economically dependent population and to invest more of their savings in improving productivity and reducing poverty (see Chapter 6). However, this window of opportunity can be used only if almost all the members of the working-age population are gainfully employed and able to save and to invest in their children’s future. High unemployment would not allow these benefits to materialize.

High-income countries currently face the problem of an aging population—that is, a growing percentage of elderly nonworking people. In 1997 people 65 and above made up 13.6 percent of the population in these countries, and this portion is expected to grow to almost 17.4 percent by 2015. In several of these countries (Belgium, Germany, Greece, Italy, Japan, Sweden) the share of elderly people has already reached or surpassed 15 percent. An aging population puts greater pressure on a country’s pension, health care, and social security systems. As life expectancy continues to increase in developing countries, they too will face the problem of an aging population (see Figure 8.3). In fact, developing countries are expected to be hit even harder because they are financially less prepared to deal with it and because the rate of growth in life expectancy and therefore population aging is much faster there than in developed countries.

The Burden of Infectious Disease

In sharp contrast to successes in controlling some of the most dangerous killers of children such as diarrhea and worm infections, other infectious diseases persist into the 21st century. For example, the average rate of measles immunization worldwide is only about 80 percent, and every year more than 1 million children die of the disease. Many of those children are in Sub-Saharan Africa, where the rate of measles immunization is the lowest—under 60 percent.

About half of all infectious disease mortality in developing countries--more than 5 million deaths a year--can be attributed to just three diseases: HIV/AIDS, tuberculosis (TB), and malaria. None of the three has an effective vaccine, but there are proven and cost-effective ways to prevent these diseases. Prevention, however, is complicated by the fact that infections occur primarily in the poorest countries and among the poorest people, perpetuating their poverty even further.

HIV/AIDS, according to United Nations Secretary General Kofi Annan, "has become a major development crisis." Despite recent medical advances there is still no cure available, while the total number of people living with HIV/AIDS has reached 40 million. In the hardest-hit low-income countries AIDS has already lowered the average life expectancy by a decade or more. Since the disease first surfaced in the late 1970s-early 1980s, about 22 million people have died from it ( including 3 million in the year 2000 alone), and 13 million children have lost one or both parents. About three-quarters of these deaths occurred in Africa, where AIDS is now the primary cause of death. In many African countries 10 to20 percent of all adults are infected with HIV. The Caribbean has the highest prevalence of HIV infection outside of Sub-Saharan Africa (in percentage terms), while in other regions HIV prevalence is considerably lower (see Data Table 3).

An extremely steep increase in the number of new HIV infections is currently being seen in the countries of Eastern Europe and Central Asia, where the epidemic arrived only in the early 1990s. Between the end of 1999 and that of 2000, the number of people living with HIV/AIDS in this region almost doubled, rising from 420,000 to more than 700,000. This is already more than in Western Europe both in absolute terms (compare with 540,000 in Western Europe) and in percentage of the total adult population (0.35 percent versus 0.24 percent). Particularly alarming is the number of new infections in this region and in Asia, although nowhere else is HIV spreading on a scale comparable with that in Sub-Saharan Africa (see Map 8.1). Note that about half of all new infections are estimated to occur in the age group 15-24.

In high-income countries, the number of AIDS-related deaths considerably decreased in the late 1990s thanks to effective therapy that is keeping infected people alive longer. However, this newly developed therapy is very expensive—from US$10,000 to US$20,000 per year--so for most people in developing countries it is utterly out of reach. Preventing new HIV infections is much more affordable, particularly in the early stage of an epidemic. Raising awareness about AIDS and simple ways of personal protection can go a long way in forestalling a full-blown national epidemic. At the same time the African countries hardest hit by HIV/AIDS cannot be expected to cope with this crisis without substantial support from the international community. According to some estimates, effectively fighting the epidemic in low- and middle-income countries would require US$10.5 billion annually, while in reality the total amount of international assistance for this purpose reached US$2.5 billion in 2003 (after increasing eight-fold since 1996).

Tuberculosis--another global epidemic-- threatens to get out of control as a result of combination with HIV/AIDS and the emergence of multi-drug-resistant TB strains. HIV radically weakens a person's immune system, and TB becomes the first manifestation of AIDS in over 50 percent of all cases in developing countries. In addition, multi-drug-resistant TB develops, caused by inconsistent and partial TB treatment. And poverty remains the main factor of TB epidemics because the probability of becoming infected and that of developing active TB are both associated with homelessness, crowded living conditions, poor air circulation and sanitation, malnutrition, psychological stress, and substance abuse. Thus TB thrives on the most vulnerable such as refugees, seasonal migrant workers, and prison inmates.

Tuberculosis kills about 2 million people a year worldwide even though modern, low-cost anti-TB drugs can cure at least 85 percent of all cases. In fact, according to World Health Organization (WHO) estimates, only 19 percent of all TB cases in 20 high TB burden countries· are currently cured. Tragically, there are more TB deaths today than at any other point in history. The main burden of TB is carried by Southeast Asia and Sub-Saharan Africa, where most of the world's poor reside (see Chapter 6). In addition, new outbreaks of TB have recently occurred in a number of countries¹ of Eastern Europe and the former Soviet Union, fueled by socioeconomic crises and growing poverty.

Malaria, a largely preventable and treatable infectious disease, nevertheless kills almost as many people as TB each year. Its spread is limited to countries with tropical climates and has shrunk considerably over the past 50 years. Former gains are being eroded, however, because of global climate warming (see Chapter 14), poorly designed irrigation projects, and multiple social crises including armed conflicts, mass movements of refugees, and disintegration of health services. As with TB, the situation is exacerbated by the emergence of multi-drug-resistant strains of the parasite. And like TB, malaria hits the poor hardest of all, because they are the least able to afford treatment as well as preventive measures: moving out of malaria-affected areas, using sprays to control mosquito nuisance, buying mosquito repellents and special bed-nets.

The total number of people suffering from malaria worldwide is estimated to be 300-500 million each year, with 90 percent of them living in Sub-Saharan Africa. Malaria exacts a particularly high toll on the poorest countries of Africa through work loss, school drop-out, cost of treatment and prevention, decreased investment, and increased social instability. According to the WHO, African countries lose 1 to 5 percent of their GDP because of malaria. By reducing the accumulation of both physical and human capital in malaria-affected countries, the disease undermines their long-term development prospects.

The most radical solution to the problem of hard-to-treat infectious diseases like HIV/TB or hard-to-prevent diseases like malaria would come from development of effective vaccines that are affordable for poor countries. But the search for low-cost vaccines to prevent diseases that affect largely the poor is generally slowed down by the highly unequal distribution of global income among countries. Pharmaceutical companies find it more profitable to invest in research and development (R&D) devoted to issues of concern primarily to developed countries, where customers are able to pay higher prices. The WHO estimates that in the early 1990s only 5 percent of all health-related R&D in the world was devoted to the health concerns of the much more populous developing world. Many experts believe that the failure of the market to provide sufficient incentives for production of such global public goods as anti-AIDS vaccine calls for action on the part of donor governments and international development institutions such as the United Nations and the World Bank (see also Chapter 13).

Lifestyle Challenges

In most middle- and high-income countries noncommunicable diseases affecting mostly people in their middle and older years are the leading cause of death. These diseases are expensive and difficult to treat, so prevention should be the main focus of public health measures. But prevention will require changing people's behaviors and lifestyles.

The importance of lifestyle choices can be illustrated by the health gap between Eastern and Western Europe. The largest contributors to this health gap are heart attacks and strokes, for which the main risk factors include unhealthy diet, lack of exercise, excessive consumption of alcohol, and smoking. All these factors, particularly smoking, are more prevalent in Eastern Europe (see Figure 8.4 and Data Table 3).

Cigarette smoke does more damage to human health than all air pollutants combined. Smoking is hazardous not only to smokers, about half of whom die prematurely from tobacco-related diseases including cancer, heart disease, and respiratory conditions, but also to “passive” smokers (those inhaling secondhand smoke). According to some estimates, passive smokers increase their risk of cancer by 30 percent and their risk of heart disease by 34 percent.

The governments of most developed countries have made efforts to reduce smoking and so lower its costs to society by introducing tobacco taxes, limiting tobacco advertising, and educating people about the risks of smoking. Cigarette taxes are highest in Western Europe. According to a 1998 report by the Worldwatch Institute, smokers in Norway pay $5.23 in taxes per pack of cigarettes, which is 74 percent of the total price. And in the United Kingdom smokers pay $4.30 in taxes, which is 82 percent of the total price. Experience in many countries has shown that tobacco taxes are effective in discouraging smoking: a 10 percent increase in cigarette prices leads to a 5 percent decrease in smoking among adults and a 6-8 percent decrease among young adults (age 15 to 21), who usually have less disposable income.

According to the same report, while in Western Europe and the United States the number of smokers is declining, in most developing countries smoking is on the rise, particularly among women and young people. European and U.S. tobacco firms, facing declining demand in their home countries, have managed to increase sales by entering underregulated and underinformed overseas markets. In the past 10 years exports of cigarettes as a share of production have doubled to 60 percent in the United Kingdom and 30 percent in the United States, the two largest exporters. If current smoking trends persist, the number of tobacco-related deaths worldwide will soar from 3 million a year today to 10 million a year in 2020, with 70 percent of the deaths occurring in the developing world.