The infant mortality rate is the probability (expressed as a rate per 1,000 live births) of a child born in a specified year dying before reaching the age of one if subject to current age-specific mortality rates. [Please confirm. This is typically defined as the number of infants dying before reaching the age of one year per 1,000 live births in a given year; Method of computation also suggests this definition.]
Goal/target addressed
Goal 4. Reduce child mortality.
Target 5. Reduce by two-thirds, between 1990 and 2015, the under-five mortality rate.
Rationale
Although the target relates specifically to under-five mortality, infant mortality is relevant to the monitoring of the target since it represents an important component of 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. Because data on the incidences and prevalence of diseases (morbidity data) frequently are unavailable, mortality rates are often used to identify vulnerable populations.
Method of computation
The indicator is the number of deaths of infants under one year of age in the indicated year per 1,000 live births in the same year.
For data from vital statistics registrations (when reliable), the number of live births and deaths in the same year of children under one year old are estimated. The number of deaths is divided by the number of births and the result is multiplied by 1,000.
For data from household surveys, infant mortality estimates are obtained directly (using birth history, as in Demographic and Health Surveys) or indirectly (Brass method, as in Multiple Indicator Cluster Surveys). When estimated indirectly the under-one mortality estimates must be consistent with the under-five mortality estimates.
Comments and limitations
The infant mortality rate is considered to be a more robust estimate than the under-five mortality rate if the information is drawn from vital statistics registration.
In developing countries, household surveys are essential to the calculation of this indicator, but there are some limits to their quality. Survey data are subject to recall error, and surveys estimating infant deaths require large samples, because such incidences are uncommon and representative households cannot ordinarily be identified for sampling. Moreover, the frequency of the surveys is generally only every three to five years. Therefore, when using household survey estimates, it is important to take sampling errors into account.
Source: UNDG. 2003. Indicators for monitoring the Millennium Development Goals: Definitions, Rationale, Concepts and sources, United Nations: New York