Spatial Analysis of the Relationship between Contraceptive Use and Under-five Mortality in Nigeria.

Abstract:

Background: Under-five mortality (U5M) in Nigeria continues to be high, while contraceptive use has not increased despite national and global commitments to improve reproductive health. This dual burden presents a significant public health concern, reflecting systemic weaknesses in linking family planning and child survival strategies. Understanding how contraceptive behaviour influences under-five mortality is essential to designing integrated interventions capable of improving maternal and child health outcomes. This study, therefore, examined the spatial dynamics between child mortality and contraceptive usage in Nigeria with a focus on the influence of geo-political contexts on both processes. The research drew attention to regional differences, considering the role of socio-cultural factors in shaping these outcomes. Methods: Data were drawn from the 2021 Nigeria Multiple Indicator Cluster Survey (MICS), a nationally representative dataset comprising 38,768 women aged 15–49 years, selected through a two-stage stratified cluster sampling design to ensure adequate precision across all six geopolitical zones. United Nations Mortpak and Life table Stata ltable techniques were used to estimate child mortality rates from censored survival data. A Spatial Bayesian geo-additive regression and the Frequentist Model were conducted to account for the geographical differences. Results: About two-thirds (62.2%) of the mothers were aged 25-34 years, 67.9% were rural residents, and 52.9% had given birth at home. The contraceptive prevalence rate (CPR) was 21.7%, while the under-five mortality rate was 101.8/1,000 live births. The spatial analysis showed regional differences in under-five mortality rates, with the northern states having higher posterior odds ratios, while states like Ogun (U5MR = 28 per 1,000; POR=1.40; 95% Crl=0.69–3.22) and Bayelsa (U5MR = 38 per 1,000; POR=1.58; 95% Crl =0.72–3.84) had lower rates posterior odds ratios. In the completely adjusted Bayesian model, use of contraceptives remained protective, where mothers who utilized contraceptives were 15% lower to experience under-five mortality (aPOR: 0.85, 95% CrI: 0.72–0.98). Conclusion: The study highlights the relationship between maternal age, education, marriage, and place of residence and use of contraception and child survival in Nigeria. Therefore, low levels of contraceptive use, remain a contributing factor to under-five mortality in Nigeria. Hence, targeted and context-defined reproductive health interventions are required to improve child survival outcomes in Nigeria.