Time-to-event analysis models including frailty effects in understanding infant and child mortality in Lesotho.

Master of Science in Statistics. University of KwaZulu-Natal, Pietermaritzburg 2016.This thesis focuses on the determinants of infant and child mortality in Lesotho. It specifically examines how infant and child mortality is related to environmen- tal, demographic and socio-economic factors. A survival analysis approach is used to analyze the determinants of child mortality. Duration or time-to-event models are easily applicable to the problem of child mortality as this class of models is able to account for problems like right-censoring, structural model- ing and time varying covariates which other classes of models, such as logistic regression, cannot handle adequately. In this application the age at the child's death is used as the time to event. Household, environmental, demographic and socio-economic factors are found to have significant impact on child mortality. Policies aimed at achieving the goal of reduced child mortality should be directed on improving the households en- vironmental and / or socio-economic status of a child for this goal to be realized. Keywords: child mortality, infant mortality, neonatal mortality, duration model, survival analysis, failure function, hazard rate