Survival and Factors Associated with Mortality Among Children with Congenital Heart Defects at the Uganda Heart Institute, Mulago National Referral Hospital

Abstract

Abstract Background Congenital heart defects (CHDs) contribute to approximately 220,000 childhood deaths globally each year, with most occurring in low- and middle-income countries. Despite advances in diagnosis and management, survival remains poor in sub-Saharan Africa due to delayed diagnosis and limited access to specialized care. In Uganda, an estimated 16,000 children are born with CHDs annually, many requiring urgent intervention. Despite this burden, evidence on survival and its determinants in Uganda remains limited. This study aimed to investigate socio-demographic and clinical factors associated with survival among children born with CHDs at the Uganda Heart Institute. Methods A retrospective cohort study was conducted using electronic patient records of children diagnosed with congenital heart defects at the Uganda Heart Institute between January 2014 and December 2018. Survival analysis was performed using the log-rank test to assess differences across groups, and the Cox proportional hazards regression model was used to identify independent predictors of mortality. Results Children residing in rural areas had a significantly higher hazard of death compared to those in urban areas (HR = 1.33; 95% CI: 1.06–1.66; p = 0.013). Underweight children had more than twice the hazard of death compared to those with normal BMI (HR = 2.07; 95% CI: 1.60–2.69; p < 0.001). Defect severity was significantly associated with survival, with moderate defects showing increased hazard relative to critical defects (HR = 1.98; 95% CI: 1.25–3.13; p = 0.004), while non-critical defects were not statistically significant. Timing of diagnosis was a strong predictor of mortality (HR = 1.67; 95% CI: 1.30–2.14; p < 0.001), indicating that delayed diagnosis increases the risk of death. Oxygen level was not significantly associated with survival. Conclusion Survival among children with congenital heart defects is significantly influenced by nutritional status, place of residence, defect severity, and timing of diagnosis. Underweight children, those from rural areas, and those diagnosed later have a higher risk of mortality. Early detection and improved nutritional support are essential to enhance survival outcomes. Strengthening early screening programs and improving access to timely diagnosis and specialized care, particularly in rural settings, are critical to reducing mortality.