Under Age Five Children Survival Times in Nigeria: A Bayesian Spatial Modelling Approach

Abstract

Background: Nigeria is among the top five countries in the world with the highest under-five mortality rates. In addition to the general leading causes of under-five mortality, studies have shown that disparities in sociocultural values and practices across ethnic groups in Nigeria influence child survival, thus there is a need for scientific validation. Methods: The approach commonly adopted in multilevel modeling of the under-five mortality rate in Nigeria is to consider child death status as a binary outcome variable. In this manner, information about the time localization of mortality risk is lost in the process. This study quantified the impact of socioeconomic and demographic factors, proximate and biological determinants, and environmental factors on the risk of under-five mortality in Nigeria using a Bayesian hierarchical hazard model with time to death outcomes. The Exponential, Gamma, Log-normal, Weibull, and Cox hazard models in a mixed effect framework with spatial components were considered, and the best model was selected for inference. In addition, the Kaplan Meier survival curve, Nelson Aalen hazard curve, and components survival probabilities were estimated. Results: Findings show that gender, maternal education, household wealth status, source of water and toilet facility, residence, mass media, frequency of antenatal and postnatal visits, marital status, place of delivery, multiple births, who decide healthcare use, use of bednet are significant risk factors of child mortality in Nigeria. The mortality risk is high among the maternal age group below 24 and above 44years, and birth weight below 2.5Kg and above 4.5Kg. The under-five mortality risk is severe in Kebbi, Kaduna, Jigawa, Adamawa, Gombe, Kanu, Kogi, Nasarawa, Plateau, Sokoto states in Nigeria. Conclusions: This study accentuates the need for special attention for the first two months after childbirth as it is the age group with the highest expected mortality. A practicable way to minimize death in the early life of children is to improve maternal health care service, promote maternal education, encourage delivery in healthcare facilities, positive parental attitude to support multiple births, poverty alleviation programs for the less privileged, and a prioritized intervention to Northern Nigeria.