Examining the impact of preceding birth intervals on child survival in Ethiopia: using shared frailty model approach

The preceding birth interval is the time between a child's birth and the conception of the next child, is essential for maternal and child well-being. Short birth intervals can lead to maternal nutritional depletion, inadequate prenatal care, and increased risks of preterm birth and low birth weight, all of which can negatively impact child survival. Approximately 5 million children under the age of five died in 2019, with the majority of these deaths occurring in low- and middle-income countries. The leading causes of mortality include neonatal conditions, pneumonia, diarrhea, and malaria, which are often exacerbated by inadequate maternal health practices. The existing challenges and barriers to promoting optimal birth spacing practices in Ethiopia to improve child survival outcomes are multifaceted. The aim of this study was to investigate how the length of the preceding birth interval influences child survival in Ethiopia, by applying parametric and parametric shared frailty models. This study was conducted based on secondary data that obtained from the Ethiopian Demographic and Health Survey. The Cox proportional hazard model, accelerated failure time (AFT) model, and parametric shared frailty models were employed for data analysis. Parametric shared frailty models were employed to analyze the relationship between preceding birth intervals and child survival. A shared frailty model accounts for unobserved heterogeneity across individuals or households by including a random effect term that captures this heterogeneity. This approach allows us to control for unmeasured factors that may influence both preceding birth intervals and child survival outcomes. Among the covariates, mother of a child living in an urban area (ϕ = 0.96; 95% CI 0.94, 0.97; p-value = 0.001), non-educated women (ϕ = 1.03; 95% CI (1.00, 1.06); p-value = 0.039), primary educated women (ϕ = 1.13; 95% CI (1.11, 1.15); p-value 0.001), age of a child (ϕ = 0.99; 95% CI (0.76.0.99; p-value = 1.02; 95% CI (1.09, 1.25; p-value = 0.027), birth interval between 2–3 years (ϕ = 1.02; 95% CI 1.09, 1.25; p-value = 0.027), birth interval > = 4 years (ϕ = 1.28; 95% p-value 0.01 significantly affected the survival of the child. The relevant variable was significantly impacted by clustering (region). Factors such as age of the child at subsequent births, Current Breastfeeding, vaccination, Mother's Age at First Birth, birth type, place of delivery at health facility, mother's education level, and interval between births positively affect child survival rates. Conversely, residing rural areas, maternal smoking habits, and mother's wealth status were associated with negative impacts on child survival. These findings underscore the need for targeted interventions and educational programs aimed at promoting optimal birth spacing practices and increasing awareness among women with short preceding birth intervals, rural residents, and those with low education to improve child survival outcome.