Survival and predictors of mortality among TB-HIV co-infected children attending ART clinics in public hospitals in Addis Ababa, Ethiopia: a retrospective cohort study.

BACKGROUND: The double burden of tuberculosis (TB) and human immunodeficiency virus (HIV) remains a major global health challenge in the twenty-first century. Children (ages 0-15 years) are particularly vulnerable to TB-HIV co-infection, exhibiting higher morbidity and mortality rates than other age groups, with the burden especially pronounced in developing countries. Approximately 75% of global TB-HIV co-infections occur in Sub-Saharan Africa. This study aimed to assess the five-year survival status and identify predictors of mortality among TB-HIV co-infected children attending antiretroviral therapy (ART) clinics in public hospitals in Addis Ababa, Ethiopia. METHODS: A facility-based retrospective cohort study was conducted in pediatric ART centers in Addis Ababa. A total of 241 TB-HIV co-infected children followed between January 1, 2019, and December 31, 2023, were included, with five-year survival outcomes recorded. Kaplan-Meier survival curves and log-rank tests were used to assess differences in survival among predictor variables. The independent effect of each predictor on time to death following TB diagnosis was estimated using Cox proportional hazards regression, with results expressed as adjusted hazard ratios (aHR) at a 5% significance level. To minimize overfitting due to the limited number of events, the final multivariable model included a parsimonious set of clinically and biologically relevant predictors. RESULTS: Of the 241 children included, 35 (14.5%) died, yielding a crude mortality rate of 3.63 per 100 child-years (95% CI: 2.61-5.07) over 962.3 child-years of follow-up. The estimated cumulative five-year survival rate after TB-HIV co-infection was 83.31% (95% CI: 77.51-87.73). Significant predictors of mortality included a CD4 count below the threshold level (aHR: 2.84; 95% CI: 1.38-5.83), a history of opportunistic infections (aHR: 5.04; 95% CI: 2.01-12.69), and fair/poor ART adherence (aHR: 5.69; 95% CI: 2.73-11.90). CONCLUSION: The five-year survival rate of TB-HIV co-infected children in this study was consistent with reports from other low- and middle-income countries. Mortality was significantly associated with low CD4 counts, a history of opportunistic infections, and suboptimal ART adherence. These findings highlight the need for early identification of immunosuppressed children, and targeted interventions are essential to improve child survival.