Life expectancy is traditionally examined in two ways:
- Life expectancy at birth reflects the overall mortality level of a population. It summarizes the mortality pattern that prevails across all age groups, including children and adolescents, adults and the elderly.
- The adult mortality rate estimates the probability of dying between the age of 15 years and 60 years (per 1000 population).
The disease burden due to noncommunicable disease among adults in the most economically productive age span is rapidly increasing in developing countries owing to ageing and health transitions. The level of adult mortality is therefore becoming an important indicator in comprehensively assessing mortality patterns in populations.
In general, poverty can be correlated with lower life expectancy, while wealthier population quintiles everywhere live longer and benefit more from health services. Similarly, the low percentage of African populations living in urban areas (37%) will affect access to health services. Formal employment opportunities and benefits, as well as wages, are likely to be lower in rural and slum areas, affecting the capacity to pay out-of-pocket to cover acute or chronic health problems. An astonishing 62% of the African population was, in 2005, categorized as living in slum or informal settlement conditions.
Life expectancy at birth
Although there has been a modest increase in overall life expectancy at birth throughout the WHO African Region, from 51 years in 1990 to 53 years in 2008, a number of African countries have experienced sharp falls in life expectancy since 1990. Of these, the largest discrepancies are seen in:
- Zimbabwe, where life expectancy has fallen from 61 years in 1990 to 42 years in 2008
- Swaziland, where life expectancy has fallen from 63 years in 1990 to 48 years in 2008
- Lesotho, where life expectancy has fallen from 61 years in 1990 to 47 years in 2008
- South Africa, where life expectancy has fallen from 63 years in 1990 to 53 years in 2008
- Botswana, where life expectancy has fallen from 67 years in 1990 to 61 years in 2008
- Congo and Kenya, where life expectancy has fallen from 60 years in 1990 to 54 years in 2008.
It is widely accepted that HIV/AIDS and other diseases brought in its wake are the main determinants of these catastrophic drops.
However, some countries have succeeded in greatly increasing their life expectancy at birth over the past 18 years, including:
- Eritrea, where life expectancy has seen increased dramatically from only 36 years in 1990 to 65 years in 2008
- Liberia, where life expectancy has increased from 36 years in 1990 to 54 years in 2008
- Madagascar, where life expectancy has increased from 52 years in 1990 to 60 years in 2008.
Only a handful of countries in the WHO African Region demonstrate the global trend for women to outlive men. In the majority of African countries, estimated life expectancy at birth for men and women does not vary widely. The overall difference throughout the Region shows that women, with a life expectancy of 54 years, gain an additional life expectancy of only 2 years more than men. Neither sex has a life expectancy at birth that approaches the global estimate for 2008 of 68 years. This points to the existence in the Region of health and social factors, including HIV/AIDS, that override the global trend for greater longevity in women. High disease burdens in general, and high reproduction and maternal and child mortality rates in particular, as well as health-seeking behaviour patterns in women, are likely to be among the contributing causes.
The figures for 2008 show the WHO African Region is trailing considerably behind other WHO Regions regarding life expectancy at birth. The 53 years of life that populations of the WHO African Region can expect at birth compares with:
- 65 years in the WHO South-East Asia Region and the WHO Eastern Mediterranean Region
- 75 years in the WHO European Region and the WHO Western Pacific Region
- 76 years in the WHO Region of the Americas.
African populations are therefore losing a full 15 years in comparison with the global average.
Healthy life expectancy at birth
The life expectancy estimates above give no cause for complacency, but the picture becomes bleaker when interpreted in respect of the healthy life expectancy at birth. The healthy life expectancy at birth concept represents the average number of years that a person can expect to live in "good health" by taking into account years lived in less than full health due to disease or injury. As a result, it captures both fatal and non-fatal health outcomes and disabilities, of which the most common worldwide are hearing loss, visual impairment and mental disorders.
Examined in accordance with the healthy life expectancy at birth concept, life expectancy at birth across the WHO African Region drops to 45 years for men and 46 years for women. This represents a drop of more than 10 years from the global healthy life expectancy at birth estimates of 58 years for men and 61 years for women. These findings have implications for the choices facing health budgeting and intervention packages, and further complicate the difficult task facing health services in designing services capable of delivering integrated measures to address infectious and noncommunicable diseases.