Survival analysis of time-to-death for under-five children in Somalia: Application of AFT modeling approach

Abstract

Objectives: Sub-Saharan Africa continues to experience the highest under-five mortality rates globally, contributing 29.7% of all under-five deaths despite a 60% global decline between 1990 and 2022. This study aims to analyze time to death among children under five in Somalia and identify the key factors influencing child survival. Study design: The data used in this study is a population-based cross-sectional survey using a multistage stratified cluster sampling design. Methods: In this study, 17,610 children under five from a Somalia 2020 demographic and health survey (DHS) were used. The accelerated failure time (AFT) model was used to analyze the time to death of under-five children. Survival time ratios (TR) and corresponding p-values were used to identify significant determinants of child survival. Results: Of the total 17,610 children, about 689 children (3.91%) experienced the event (death). Several AFT models were compared, and the Weibull AFT model was selected as the best fit. The results of the Weibull AFT model showed that significant factors that influence child survival include maternal age at the first birth, preceding birth interval, the number of children ever born, and regional disparities. Longer birth intervals (18-59 months) increased survival time for the children, while shorter or excessively long intervals reduced survival. Mothers aged 20-29 at first birth showed a 49.2% increase in survival time (TR = 1.492; p = 0.003), compared to the younger mother. The shape parameter (0.607) suggests a declining hazard rate over time. Conclusions: This study highlights critical maternal, familial, and regional factors that influence child survival in Somalia. Strengthening targeted interventions, particularly those promoting optimal birth spacing and supporting younger mothers, may substantially improve under-five children survival outcomes.