Background: Despite modest improvements in child health outcomes during the
20th century, infant and child mortality rates remain unacceptably high in Nigeria.
With about 1 in 6 children dying before the age of five, Nigeria, like many other
countries in sub-Saharan Africa, is not on track to achieve the Millennium
Development Goal 4 (MDG 4) (i.e. reducing childhood mortality by 2015). Nigeria’s
under-five mortality rate is among the highest in the world. Addressing poor infant
and child health outcomes requires scientific evidence on how best to tackle its
determinants. Literature shows that knowledge about the determinants of child
mortality at the individual level is insufficient to address the problem. This is because
the characteristics of the household and community context where a child is born or
raised tend to modify individual-level factors and therefore affect child survival.
However, there are gaps in evidence on the effects of characteristics of the
community contexts on child survival in Nigeria. Hence, this study examined the
contextual determinants of infant and child mortality in Nigeria with a focus on
individual, household and community-level characteristics. The study addressed
three specific objectives: (1) to examine the levels and magnitudes of infant and
child mortality in Nigeria; (2) to identify the individual, household, and communitylevel
factors associated with infant and child mortality in Nigeria; and (3) to
determine the extent to which the contextual factors account for regional variations
in infant and child mortality in Nigeria.
Methodology: The study utilized data from 2003 and 2008 Nigeria Demographic
and Health Survey (NDHS). The target population for this study (women aged 15-49
years who had at least a live birth in the five years preceding the survey) were
extracted from the whole 2003 and 2008 NDHS datasets. Out of the survey’s total
sample size of 7620 women contained in 2003 dataset, analysis was restricted to the
live born children of 3775 women amounting to 6028 live births within the five years
before the survey. Similarly, from a total of 33,385 women contained in 2008
dataset, analysis was restricted to the live born children of 18,028 women who were
28,647 children delivered in the five years before 2008 survey. In order to achieve
the objectives of this study, analysis was restricted to births in the five years before
the survey. All analyses were completely child-based. That is, child was the unit of
analysis. The dependent variables in this study are: (i) infant mortality – defined as
the risks of dying during the first year of life; (ii) child mortality – defined as the risk
of dying between ages 12 and 59 months; and (iii) under-five mortality – defined as
the risks of dying between birth and the fifth birthday. All the outcome variables
were measured as the duration of survival since birth in months. Guided by the
reviewed literature and the conceptual framework, relevant independent variables
were selected at the individual-, household- and community-levels. Three levels of
analysis – univariate, bivariate and multivariate – were conducted. At the
multivariate level, Cox proportional hazards regression analysis was employed
because of its suitability for analysing time-to-event data and censored observations.
In addition, using generalized linear latent and mixed models (GLLAMM)
implementable in Stata, multilevel survival analysis was employed to consider the
hierarchical structure of the DHS mortality data; and to identify contextual factors
xxi
influencing regional variations in infant and child mortality in Nigeria. Data were
analyzed using Stata software (version 11.1). Indirect estimations were obtained
using MortPak-Lite, Microsoft Excel, and Model Life Tables.