A Retrospective Cross-Sectional Study on the Determinants of Post-Neonatal Under-Five Mortality (U5M) in Kota Kinabalu, Sabah: Analysis of Under-Five Mortality Data from 2020 to 2024

Abstract

Introduction: Under-five mortality (U5M) is a key indicator of child health and socio-economic development. Despite global efforts to reduce child deaths, disparities persist, especially in marginalized regions such as Sabah, Malaysia.

Objectives: This study focuses on identifying the determinants of post-neonatal U5M (children aged 1–59 months) in Kota Kinabalu, Sabah.

Methods: A retrospective cross-sectional study was conducted using mortality data from the Kota Kinabalu District Health Office from 2020 to 2024. All eligible post-neonatal death cases were included through total population sampling. Data were extracted using a structured form and analysed using descriptive statistics, chi-square tests, and multivariate logistic regression in R software.

Results: Infants aged 1–11 months accounted for most deaths. Citizenship status was significantly associated with preventable deaths, with non-citizen children having higher odds of preventable mortality compared to Malaysian citizens (adjusted OR: 0.43; 95% CI: 0.24–0.74; p = 0.003). Each additional week of gestation increased the odds of preventable death (adjusted OR: 1.15; 95% CI: 1.06–1.25; p = 0.001). The final logistic regression model demonstrated fair discriminatory power with an AUC of 0.713.

Conclusions: The study showed significant inequalities in post-neonatal U5M among non-citizen populations and emphasizes the need for improved access to healthcare, maternal education, and antenatal care. These findings can inform targeted policies and public health interventions to reduce preventable child mortality and support progress toward Sustainable Development Goal 3.2.