Time to first birth and its determinants among female youths in Ethiopia using accelerated failure time shared frailty models

Abstract

Early motherhood is associated with increased public health risks, which can significantly influence a woman’s life trajectory and opportunities. Despite ongoing efforts to reduce youth pregnancies, the prevalence of early childbirth remains a major challenge, affecting not only potential health outcomes but also broader social and economic consequences. Although several studies have examined fertility trends, most have focused on all age groups, and much of the available evidence is outdated. Moreover, up-to-date studies specifically focusing on female youths aged 15–24, a group at high risk for early childbearing, are limited. Therefore, this study aimed to identify the determinants of time to first birth among female youths in Ethiopia using the 2019 Ethiopia Mini Demographic and Health Survey. A total of 3,691 female youth aged 15–24 were included in the analysis. The Kaplan-Meier method was used to estimate the time to first birth, a log-rank test was used to compare the difference in survival curves. AFT models with gamma and inverse Gaussian frailty distributions was applied to identify significant determinant of time to first birth, with model selection based on the Akaike Information Criterion. The Weibull inverse Gaussian shared frailty model was the best fit model since it had a low Akaike Information Criterion. Overall, median survival time was 20 years (IQR: 19, 21). The significant determinants of time to first birth were richest wealth index (ϕ = 1.552, 95% CI: 1.211–1.989), knowledge of at least one method (ϕ = 1.284, 95% CI: 1.163–1.625), use of contraceptives (ϕ = 2.673, 95% CI: 1.809–3.951), rural residence (ϕ = 0.765, 95% CI: 0.616–0.951), secondary educational (ϕ = 1.242, 95% CI: 1.028–1.501) and higher educational (ϕ = 1.286, 95% CI: 1.122–1.475). Addressing these issue through targeted policies and improved access to education and reproductive health services is key to reducing early pregnancies and enhanceng youth well-being in Ethiopia.