Short name:
Infant mortality rate (IMR)
Topic:
Mortality and burden of disease
Rationale:
Infant mortality represents an important component of under-five mortality. Like under-five mortality, infant mortality rates measure child survival. They also reflect the social, economic and environmental conditions in which children (and others in society) live, including their health care. Since data on the incidence and prevalence of diseases (morbidity data) frequently are unavailable, mortality rates are often used to identify vulnerable populations. Infant mortality rate is an MDG indicator.
Definition:
Infant mortality rate is the probability of a child born in a specific year or period dying before reaching the age of one, if subject to age-specific mortality rates of that period. Infant 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 1000 live births.
Disaggregation:
Age : 0-27 days, Age : 28 days - <1 year
Method of measurement
Most frequently used methods using the above-mentioned data sources are as follows: • Civil registration: Number of deaths at age 0 and population for the same age are used to calculate death rate which are then converted into age-specific probability of dying. • 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 infant 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.
Method of estimation:
The Inter-agency Group for Child Mortality of Estimation (UN IGME) which includes representatives from UNICEF, WHO, the World Bank and the United Nations Population Division, produces trends of infant mortality rates with standardized methodology by group of countries depending on the type and quality of source of data available. For countries with adequate trend of data from civil registration, the calculations of under-five and infant mortality rates are derived from a standard period abridged life table. For countries with survey data, since infant mortality rates from birth histories of surveys are exposed to recall biases, infant mortality is derived from the projection of under-five mortality rates converted into infant mortality rates using the Bayesian B-splines bias-adjusted model. These infant mortality rates have been estimated by applying methods to all Member States to the available data from Member States, that aim to ensure comparability of across countries and time; hence they are not necessarily the same as the official national data. Predominant type of statistics: adjusted and predicted.
Method of estimation of global and regional aggregates:
Global and regional estimates are derived from numbers of estimated deaths and population for age groups 0 year, aggregated by relevant region.
Preferred data sources:
Civil registration with complete coverage
Unit of Measure:
Deaths per 1000 live births
Expected frequency of data dissemination:
Annual
Expected frequency of data collection:
Annual
Comments:
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 civil registration systems (completeness of registration) and high quality of survey or census data collection are crucial - WHO does estimate the level of underestimation of civil registration systems and there clearly is substantial variation in data quality and consistency across countries. Censuses and surveys can provide detailed disaggregation. Often disaggregated under-five mortality rates from household surveys are presented for 10-year periods because of the rapid increase in sampling error if multiple categories are used. Civil registration data usually does not include socio-economic variables but can provide the other disaggregation. 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 civil registration systems (completeness of registration) and high quality of survey or census data collection are crucial - WHO does estimate the level of underestimation of civil registration systems and there clearly is substantial variation in data quality and consistency across countries. These infant mortality rate have been estimated by applying methods to all Member States to the available data from Member States, that aim to ensure comparability of across countries and time; hence they are not necessarily the same as the official national data.