Health Status Statistics: Mortality
Maps and graphs
Probability of dying (per 1000) under age five years (under-5 mortality rate)
Rationale for use
mortality rate is a leading indicator of the level of child health and
overall development in countries. It is also a MDG indicator.
Probability of a
child born in a specific year or period dying before reaching the age
of five, if subject to age-specific mortality rates of that period.
Under-5 mortality rate,
is strictly speaking, not a rate (i.e. the number of deaths divided by
the number of population at risk during a certain period of time) but a
probability of death derived from a life table and expressed as rate
per 1,000 live births.
Live birth refers
to the complete expulsion or extraction from its mother of a product of
conception, irrespective of the duration of the pregnancy, which, after
such separation, breathes or shows any other evidence of life - e.g.
beating of the heart, pulsation of the umbilical cord or definite
movement of voluntary muscles - whether or not the umbilical cord has
been cut or the placenta is attached. Each product of such a birth is
considered live born.
mortality rates among children and infants are calculated from birth
and death data derived from vital registration, census, and/or
Vital registration: Number of deaths by age and numbers of births and
children in each age group are used to calculate age specific rates.
This system provides annual data.
Census and surveys: An indirect method is used based on questions to
each woman of reproductive age as to how many children she has ever
born and how many are still alive. The Brass method and model life
tables are then used to obtain an estimate of under-5 mortality.
Surveys: A direct method is used based on birth history - a series of
detailed questions on each child a woman has given birth to during her
lifetime. To reduce sampling errors, the estimates are generally
presented as period rates, for five or 10 years preceding the survey.
Methods of estimation
data from different sources are consolidated to obtain estimates of the
level and trend in under-5 mortality by fitting a curve to the observed
mortality points. However, to obtain the best possible estimates,
judgement needs to be made on data quality and how representative it is
of the population. Recent statistics based on data availability in most
countries are point estimates dated by at least 3-4 years which need to
be projected forward in order to obtain estimates of under-5 mortality
for the current year.
By sex, location
(urban/rural, major regions/provinces) and socio-economic
characteristics (e.g. mother's education, wealth quintile). Often
disaggregated under-5 mortality rates are presented for 10-year periods
because of the rapid increase in sampling error if multiple categories
are used. Censuses and surveys provide such detail; vital registration
data usually does not include socio-economic variables but can provide
the other disaggregations.
Trends in child mortality in the developing world: 1960 to 1996
Hill K, et al. Trends in child mortality in the developing world: 1990 to 1996, unpublished report, United Nations Childrens' Fund (UNICEF), New York, January 1998.
The World Health Report 2005, Make every mother and child count
The World Health Report 2005, Make every mother and child count. Geneva, World Health Organization, 2005.
The State of the World's Children 2005 - Childhood under threat
The State of the World's Children 2005 - Childhood under threat. New York, United Nations Childrens' Fund (UNICEF), 2004.
Demographic and Health Surveys (DHS)
WHO Mortality Database (Vital registration data)
UNICEF (statistics and MICS)
Even though many
countries have collected information on child mortality in recent
years, the high demand for very recent child mortality trend
information is difficult to meet through household surveys. High
quality of vital registration systems (completeness of registration)
and high quality of survey or census data collection are crucial - WHO
does estimate the level of underestimation of vital registration
systems and there clearly is substantial variation in data quality and
consistency across countries.