Global and Regional Mortality in 2001
Slightly more than 56 million people died in 2001, 10.5 million, or nearly 20 percent, of whom were children younger than five. Of these child deaths, 99 percent occurred in low- and middle-income countries. Those age 70 and over accounted for 70 percent of deaths in high-income countries, compared with 30 percent in other countries. Thus, a key point is the comparatively large number of deaths among the young and the middle-aged in low- and middle-income countries. In these countries, 30 percent of all deaths occur at ages 15 to 59, compared with 15 percent in high-income countries. The causes of death at these ages, as well as in childhood, are thus important in assessing public health priorities.
This section provides an overview of global and regional causes of death in 2001. Note that as described earlier, the results reported here are tabulated by underlying disease cause or external cause of injury. Total attributable deaths for some diseases that increase the risk of other diseases or injuries will be substantially larger than the estimates of direct deaths given here. Chapter 4 estimates deaths attributable to 26 global risk factors. The tables in annex 3B provide detailed tabulations of deaths by cause and sex for regions, for low- and middle-income countries, for high-income countries, and for the world.
Distribution of Deaths by Major Cause Group
Worldwide, one death in every three is from a Group I cause. This proportion remains almost unchanged from 1990 with one big difference: whereas HIV/AIDS accounted for only 2 percent of Group I deaths in 1990, it accounted for 44 percent of Group I deaths in 2001. Excluding HIV/AIDS, Group I deaths fell from 33 percent of total deaths in 1990 to less than 20 percent in 2001. Virtually all the Group I deaths are in low- and middle-income countries. Just under 10 percent are from Group III causes (injuries) and almost 60 percent of deaths are from Group II causes (noncommunicable diseases).
Figure 3.5
shows the proportional distribution of these major cause groups for low- and middle-income countries and high-income countries.
[Figure
3.5]
Group I causes remain the leading cause of child deaths in all regions, although they are now responsible for fewer child deaths than Group II and Group III combined in high-income countries (
figure 3.6
). In contrast, Group II causes are now responsible for more than 50 percent of deaths in adults ages 15 to 59 in all regions except South Asia and Sub-Saharan Africa, where Group I causes, including HIV/AIDS, remain responsible for 33 and 67 percent of deaths, respectively. For adults ages 15 to 59, death rates from Group II causes are higher for all low- and middle-income regions than for high-income countries, and in Europe and Central Asia are almost double the rate for the high-income countries. These results show that premature mortality from noncommunicable diseases is higher in populations with high mortality and low incomes than in the high-income countries.
[Figure
3.6]
Leading Causes of Death
Table 3.6 shows the top 10 disease and injury causes of death in 2001 for low- and middle-income countries and for high-income countries. IHD and cerebrovascular disease (stroke) were the leading causes of death in both groups of countries in 2001, responsible for 12 million deaths globally, or almost one-quarter of the global total. Only 1.4 million of the 7.1 million who died of IHD were in the high-income countries. Stroke killed 5.4 million, of whom less than 1.0 million were in high-income countries.
[Table .]
Whereas lung cancer, predominantly due to tobacco smoking, remains the third leading cause of death in high-income countries, reflecting high levels of smoking in previous years, the increasing prevalence of smoking in low- and middle-income countries has not yet driven lung cancer into the top 10 causes of death for these countries. HIV/AIDS is the fourth leading cause of death in low- and middle-income countries, and HIV/AIDS death rates are projected to continue to rise, albeit at a slower pace, despite recent increased efforts to improve access to antiretroviral drugs.
Lower respiratory infections, conditions arising during the perinatal period, and diarrheal diseases remain among the top 10 causes of death in low- and middle-income countries. In 2001, these three causes of death together accounted for nearly 60 percent of child deaths globally.
Table 3.7 shows the 10 leading causes of death in low-and middle-income countries by sex in 2001. Leading causes of death are generally similar for males and females, although road traffic accidents appear in the top 10 only for males and diabetes appears only for females.
[Table .]
Leading Causes of Death in Children.
Infectious and parasitic diseases remain the major killers of children in the developing world. Although notable success has been achieved in certain areas, for example, polio, communicable diseases still account for 7 out of the top 10 causes and are responsible for about 60 percent of all child deaths. Overall, the 10 leading causes in low- and middle-income countries represent 80 percent of all child deaths in those countries, and also worldwide ( table 3.8 ).
[Table .]
Many Latin American and some Asian and Middle Eastern countries have shifted somewhat toward the cause of death pattern observed in developed countries. In these countries, conditions arising during the perinatal period, including birth asphyxia, birth trauma, and low birthweight, have replaced infectious diseases as the leading cause of death and are now responsible for 21 to 34 percent of deaths. Such a shift in the cause of death pattern has not occurred in Sub-Saharan Africa, where perinatal conditions rank in fourth place and malaria, lower respiratory infections, and diarrheal diseases continue to be the leading causes of death in children, accounting for 53 percent of all deaths.
About 90 percent of all HIV/AIDS and malaria deaths in children in developing countries occur in Sub-Saharan Africa, which accounts for 23 percent of the world's births and 42 percent of the world's child deaths. The immense surge of HIV/AIDS mortality in children in recent years means that HIV/AIDS is now responsible for 332,000 child deaths annually in Sub-Saharan Africa and nearly 8 percent of all child deaths in the region.
Some progress has been made against diarrheal diseases and measles in low- and middle-income countries. While the incidence of diarrheal diseases is thought to have remained stable, mortality from diarrheal diseases has fallen from 2.5 million deaths in 1990 to about 1.6 million deaths in 2001, and now accounts for 13 percent of all deaths of children under age 15. Deaths from measles have declined modestly, although more than half a million children under five still died from this disease in 2001. Malaria causes more than a million child deaths per year or nearly 11 percent of all deaths of children under five.
Leading Causes of Death in Adults
Table 3.9 shows the leading causes of deaths among adults ages 15 to 59 worldwide in 2001. Despite a global trend of declining communicable disease burden in adults, HIV/AIDS has become the leading cause of mortality and the single most important contributor to the burden of disease among adults in this age group.
[Table .]
Nearly 80 percent of the 2.1 million adult deaths from HIV/AIDS in 2001 occurred in Sub-Saharan Africa. In this region, HIV/AIDS is the leading cause of death, resulting in more than 6,000 deaths every day and accounting for almost one in five deaths for all ages and one in two deaths of adults ages 15 to 59. HIV/AIDS has reversed mortality trends among adults in the region, and in many countries, life expectancies have declined since 1990.
The 4.5 million adult injury deaths in 2001 were heavily concentrated among young adults, particularly men. In the 15 to 59 age group, road traffic accidents and suicide were among the 10 leading causes of death in high-income and low- and middle-income countries, and violence (homicide) was also among the 10 leading causes in low- and middle-income countries. Among adults ages 15 to 44 worldwide, road traffic accidents were the leading cause of death for men after HIV/AIDS, followed by TB and violence. Suicide was the third leading cause of death for women in this age group, after HIV/AIDS and TB, with road traffic accidents in fifth place.
The risk of death rises rapidly with age among adults age 60 and over in all regions. Globally, 60-year-olds have a 55 percent chance of dying before their 70th birthday. Regional variations in the risk of death are smaller at older ages than at younger ages, ranging from around 40 percent in the developed countries of Western Europe to 60 percent in most developing regions and 70 percent in Sub-Saharan Africa. Historical data from countries such as Australia and Sweden show that life expectancy at age 60 changed slowly during the first six to seven decades of the 20th century, but started to increase substantially since around 1970. Life expectancy at age 60 has now reached 25 years in Japan. In Eastern Europe from 1990 onward, Hungary and Poland started to experience similar improvements in mortality for older people, but Russia has not, and is actually experiencing a worsening trend.
Regional Variations in Causes of Death
The tables in annex 3B show total deaths by age, sex, and cause for each of the regions and the world. The 10 leading causes of mortality differ greatly among low-income and middle-income countries ( table 3.10 ) and between them and high-income countries ( table 3.6 ). IHD and cerebrovascular disease are among the top four causes of death in all low- and middle-income regions except Sub-Saharan Africa, where they are eighth and seventh, respectively. Cerebrovascular disease is the leading cause of death in East Asia and the Pacific, unlike in most other regions, where IHD causes more deaths than cerebrovascular disease. In Sub-Saharan Africa, 6 of the top 10 causes are communicable diseases, with HIV/AIDS being the leading cause of death, followed by malaria and lower respiratory infections.
[Table .]
South Asia (mainly India) and Latin America and the Caribbean are the only two other low- and middle-income regions where HIV/AIDS is one of the top 10 causes of death. Lower respiratory infections, primarily pneumonia, are the third leading cause of death, especially among children under five, who account for 60 percent of these deaths. Chronic obstructive pulmonary disease kills more people (1.4 million) in the East Asia and Pacific region, primarily China, than anywhere else in the world, with 50 percent of global mortality from the disease occurring there.
Europe and Central Asia differs from all other low- and middle-income regions in the size of the CVD epidemic (with almost 50 percent of deaths due to CVD), followed by trachea, bronchus, and lung cancers in third place. Self-inflicted injuries (suicide) are the fifth leading cause of death in this region. South Asia is the only other region where suicide is in the top 10 causes of death. Latin America and the Caribbean is distinguished as the only region where violence falls in the top 10 causes of death, responsible for 1 in 25 deaths. In all low- and middle-income regions apart from Europe and Central Asia, road traffic accidents are included among the top 10 causes of death, reaching fifth position in the Middle East and North Africa, where they are responsible for 1 in 20 deaths.
Years of Life Lost Due to Premature Death
In contrast to crude numbers of deaths, a time-based measure such asYLL allows us to identify those causes that account for premature deaths by giving greater weight to deaths at younger ages. Thus, while noncommunicable diseases accounted for nearly 60 percent of deaths globally in 2001, they accounted for only 40 percent of YLL, whereas injuries accounted for 12 percent of YLL and 9 percent of deaths.
Figure 3.7
compares the 10 leading causes of YLL and 10 leading causes of death for 2001. YLL give relatively greater importance to HIV/AIDS, perinatal conditions, and diarrheal diseases, whereas counts of deaths give relatively greater importance to IHD, stroke, and chronic obstructive pulmonary disease.
[Figure
3.7]
