Survival and factors associated with mortality among children with congenital heart defects at the Uganda Heart Institute, Mulago National Referral Hospital

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 cardiac care. In Uganda, CHDs contribute substantially to childhood morbidity and mortality, yet evidence on survival patterns and factors associated with mortality remains limited. This study investigated socio-demographic and clinical factors associated with survival among children diagnosed with CHDs at the Uganda Heart Institute. 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. 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. Compared with critical defects, moderate defects were associated with a higher hazard of death (HR = 1.98; 95% CI: 1.25–3.13; p = 0.004), although this finding should be interpreted cautiously. Non-critical defects were not significantly associated with mortality. Timing of diagnosis was significantly associated with mortality (HR = 1.67; 95% CI: 1.30–2.14; p < 0.001), with later diagnosis associated with a higher hazard of death. Oxygen level was not significantly associated with survival. Survival among children with congenital heart defects was significantly associated with nutritional status, place of residence, defect severity, and timing of diagnosis. Underweight children, those from rural areas, and those diagnosed later were observed to have a higher hazard of death. Early detection and improved nutritional support may contribute to improved survival outcomes. Strengthening early screening programs and improving access to timely diagnosis and specialized care, particularly in rural settings, are critical to reducing mortality.