Indicators

Life expectancy at birth reflects the overall mortality level of a population. It summarizes the mortality pattern that prevails across all age groups - children and adolescents, adults and the elderly.

The average number of years that a newborn could expect to live, if he or she were to pass through life exposed to the sex- and age-specific death rates prevailing at the time of his or her birth, for a specific year, in a given country, territory, or geographic area.

Sex

Life expectancy at birth is derived from life tables and is based on sex- and age-specific death rates. Life expectancy at birth values from the United Nations correspond to mid-year estimates, consistent with the corresponding United Nations fertility medium-variant quinquennial population projections.

Impact

Procedures used to estimate WHO life tables for Member States vary depending on the data available to assess child and adult mortality. Four country categories have been used for this revision. In all three cases, UN-IGME estimates of neonatal, infant and under-5 mortality rates were used.   1)  Countries with high HIV for which WPP2015 used Spectrum to explicitly model HIV mortality. The UN Population Division has provided unpublished estimates of non-HIV mortality for these countries.   2) Countries with significant HIV epidemics for which WHO has in the past explicitly modelled HIV and non-HIV mortality trends in order to prepare life tables. These countries were not modelled using Spectrum for WPP2015.   3) Countries for which the WHO Mortality Database held mortality data from vital registration (VR) systems for 75% or more of years since 1990.   4) Countries where interpolated mortality rates from WPP quinquennial life tables were used directly to construct annual life tables     Predominant type of statistics: Predicted

The numbers of deaths estimated from life table and population by age groups  are aggregated by relevant region in order to compute regional life tables

Years

Biennial (Two years)

Biennial (Two years)

The lack of complete and reliable mortality data, especially for low income countries and particularly on mortality among adults and the elderly,  necessitates the application of modelling (based on data from other populations) to estimate life expectancy. This may lead to minor differences compared with official life tables prepared by Member States.