Modelling child mortality and its environmental impact in Nigeria

Abstract

Nigeria has the world's second highest rate of deaths under 5 years of age, following India. This high rate of under-5 mortality in Nigeria can be attributed to demographic, socioeconomic, and environmental factors because children younger than 5 years are vulnerable to environmental health hazards. This thesis used the Cox proportional hazards regression model to examine risk factors for child mortality and its environmental determinants in Nigeria. Specifically, this thesis aimed to examine the following: (1) the relationship between socioeconomic and demographic factors and neonatal mortality; (2) common factors associated with post-neonatal, infant, child, and under-5 mortality, (3) the effect of water and sanitation on childhood mortality, and (4) the effect of solid fuel use on death of children under 5 years old. The data used in addressing these specific aims were the 2003, 2008, and 2013 Nigeria Demographic and Health Surveys. Additionally, published papers that addressed the research aims have been integrated to form the core of this thesis. The determinants of neonatal mortality in Nigeria were analysed and are reported in Chapter 3. There was an increased risk of neonatal death related to mothers younger than 20 years, mothers residing in rural areas, a small or very small newborn size, and newborns delivered by caesarean section. Additionally, fourth or higher birth order of newborns with a short birth interval 2 years was significantly associated with neonatal mortality. Chapter 4 focuses on the common factors associated with post-neonatal, infant, child, and under-5 mortality. A decreased level of risk of mortality across the four age ranges was associated with children born to mothers who had a secondary or higher education, and mothers residing in urban areas. The risk of mortality was also decreased for children born to mothers from rich households. Chapter 5 presents the effect of water and sanitation at 0-28 days (neonatal), 1-11 months (post-neonatal), and 12-59 months (child) by combining the three most recent Nigeria Demographic and Health Survey (NDHS) data sets. Unimproved water and sanitation significantly increased the risk of post-neonatal and child mortality. Common factors associated with under-5 mortality included household wealth index (middle and poor) and current breastfeeding status. Chapter 6 shows the effect of household use of solid fuel on neonatal, post-neonatal, and child mortality by using the 2013 NDHS data set. A total of 0.8% of neonatal deaths, 42.9% of post-neonatal deaths, and 36.3% of child deaths could be attributed to the use of solid fuels. In addition to the effect of solid fuels on childhood mortality, living in rural areas and poor households were associated with an increased risk of death during the three mortality periods. In summary, findings from these four studies highlight the need for policy-makers and public health researchers to direct resources to the most vulnerable segments of the population, and thus make better use of resources in Nigeria. However, community-based education interventions are also required to reduce avoidable child deaths and interventions should target households with a low socioeconomic status.

Date of Award	2015
Original language	English