Clinical determinants of neonatal mortality at a tertiary hospital in a resource limited setting: a retrospective cohort study

Abstract

Neonatal mortality remains a significant public health challenge in low-resource settings. Understanding the independent predictors of neonatal death is essential for developing targeted interventions and improving clinical outcomes. This study aimed to identify factors associated with neonatal mortality among admitted neonates at a tertiary hospital in Zambia, with particular emphasis on distinguishing independent factors associated with mortality from clinical indicators that primarily reflect the severity of illness. A retrospective hospital-based cohort study was conducted involving 435 neonates. Data were collected on maternal demographics, pregnancy-related complications, neonatal characteristics, and treatment modalities. Bivariate analysis was performed using Mann-Whitney U test for continuous variables and Chi-square or Fisher’s exact test for categorical variables. Variables with p < 0.05 in bivariate analysis were entered into a multivariable logistic regression model to identify independent predictors of neonatal mortality. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) were calculated. The overall neonatal mortality rate was 22.1% (96/435). In the multivariable analysis, birth weight emerged as the strongest protective factor, with each kilogram increase independently reducing the odds of death by 54% (AOR 0.46, 95% CI: 0.27–0.80, p = 0.006). Oxygen therapy was the most dominant independent risk factor (AOR 4.46, 95% CI: 1.85–10.7, p = 0.001). Notably, neonatal prematurity demonstrated a paradoxical reversal, appearing harmful in univariate analysis (OR 2.85, 95% CI: 1.78–4.55) but protective after adjustment (AOR 0.23, 95% CI: 0.08–0.65, p = 0.005), suggesting that the clinical label of “prematurity” may trigger specialized care that improves survival. Maternal hypertensive disorders (hypertension and preeclampsia) lost significance after adjustment, indicating they exert their effects indirectly through low birth weight and prematurity. Birth weight was most strongly associated with neonatal survival, while oxygen requirement identified a high-risk subgroup of neonates requiring intensive respiratory support. The paradoxical reversal of the prematurity association after adjustment likely reflects collinearity and model overadjustment; this finding should be interpreted cautiously. Interventions targeting low birth weight infants and those requiring respiratory support may yield the greatest reductions in neonatal mortality.