Neonatal mortality rate

Rationale

Mortality during the neonatal period accounts for a large proportion of child deaths, and is considered to be a useful indicator of maternal and newborn neonatal health and care. Generally, the proportion of neonatal deaths among child deaths under the age of five is expected to increase as countries continue to witness a decline in child mortality.

Definition

Number of deaths during the first 28 completed days of life per 1000 live births in a given year or other period. Neonatal deaths (deaths among live births during the first 28 completed days of life) may be subdivided into early neonatal deaths, occurring during the first 7 days of life, and late neonatal deaths, occurring after the 7th day but before the 28th completed day of life.

Method of measurement

Data from civil registration: The number of live births and the number of neonatal deaths are used to calculate age-specific rates. This system provides annual data. Data from household surveys: Calculations are based on full birth history, whereby women are asked for the date of birth of each of their children, whether the child is still alive, and if not the age at death

Method of estimation

To ensure consistency with mortality rates in children younger than 5 years (U5MR) produced for the United Nations by the Inter-agency Group for Mortality Estimation (IGME) and to account for variation in survey-to-survey measurement errors, country data points for U5MR and the neonatal mortality rate (NMR) were rescaled for all years to match the latest time series estimates of U5MR produced by IGME. This rescaling assumes that the proportionate measurement error in NMR and U5MR is equal for each data point. The following multilevel statistical model was then applied to estimate neonatal mortality rates log(NMR/1000) = α0+ β1log(U5MR/1000) + β2([log(U5MR/1000)]^2) with random effects parameters for both level and trend regression parameters, and random effects parameters influenced by country itself. For countries with high quality civil registration data for neonatal deaths, defined as i) 100% complete for adults and only civil registration data is used for child mortality; ii) population greater than 800 000; iii) and with at least 3 civil registration data points for all the following calendar windows 1990-1994, 1995-1999, 2000-2004, 2005 onwards, we used the same basic equation, but with random effects parameters for both level and trend regression parameters, and random effects parameters influenced by country itself. Predominant type of statistics: adjusted and predicted These neonatal rates are estimates, derived from the estimated UN IGME neonatal rate and infant population from World Population Prospects to calculate the live births; hence they are not necessarily the same as the official national statistics. See the estimation methods in the links section for more information.