Abstract
Background/Objectives: Tuberculosis (TB) and HIV co-infection pose significant challenges in resource-limited settings, contributing to multi-drug-resistant TB when treatment fails. This study aimed to identify determinants of TB treatment outcomes among HIV/TB co-infected patients in Lusaka, Zambia. Methods: A retrospective cohort study was conducted at Chilenje, Chipata, and Chawama level one hospitals, using systematic sampling to select 586 patient files. Data were analyzed with SPSS version 23, employing descriptive statistics, chi-square tests, and hierarchical logistic regression. Results: Among the study population (n = 586), consisting predominantly of working-age adults (25-44 years: 61.6%) and males (56.5%), treatment success was 81.3%, with a 12.5% mortality rate across treatment phases. Baseline smear-negative TB, viral load (100,000-199,999 copies/mL), diabetes without hypertension, and negative smear at follow-up independently predicted treatment outcomes. Higher treatment failure odds were linked to smear-negative TB, high viral load, and hypertension-diabetes comorbidity, while CD4 count and HIV treatment status showed no independent effects. Conclusions: These findings underscore the influence of viral load, TB type, comorbidities, and sputum conversion on treatment success, emphasizing the need for targeted monitoring and integrated care, particularly in the continuation phase, to enhance outcomes in this vulnerable population.