Evaluating tuberculosis treatment outcomes and predictors in five Southern African countries: A multi-country cohort analysis

Introduction: Despite global progress in tuberculosis (TB) control, treatment outcomes remain suboptimal, particularly in high-burden settings and among people with HIV or drug-resistant TB. Identifying predictors of unsuccessful treatment is essential to improve TB care and policy. Methods: We evaluated TB treatment outcomes and patient characteristics associated with unsuccessful outcomes in five cohorts of the International epidemiology database to evaluate AIDS (IeDEA); Center for Infectious Disease Research, Zambia; Chiure health center, Mozambique; Martin Preuss Center, Lighthouse clinic, Malawi; Masvingo health center Zimbabwe; and Themba Lethu clinic, Hellen Joseph hospital, South Africa. We included all patients with TB aged 15 years starting TB treatment and assessed their treatment outcomes in association with sociodemographic and clinical characteristics using multivariable mixed-effects models. Unsuccessful outcomes were defined as death, loss to follow-up and treatment failure. Results: Among 1438 people with TB, median age was 39 years, 67% males, 40% with HIV, and 4% with MDR-TB; 1151 (80%) treatment outcomes were successful (606 cured and 545 completed treatment), 221 (15%) unsuccessful (89 deaths, 129 loss to follow-up and 3 treatment failures), and 66 (5%) other (49 unknown and 17 transfer-outs). Unsuccessful outcomes were more probable among people with multidrug-resistant TB (MDR-TB) and among participants without formal education. Risk of death was lower for people with bacteriologically confirmed TB (adjusted odds ratio (aOR) 0.5, 95%-credible interval [CI] 0.25-0.80), those with a secondary or higher education (aOR 0.3, 95%-CI 0.13-0.69) and BMI 318 kg/m{superscript 2} (aOR 0.6, 95%-CI 0.36-0.99). MDR-TB was associated with an increase (aOR 2.4 95%-CI 1.17-4.97) and primary and secondary or higher education with a decrease in loss to follow-up (aOR 0.3, 95%-CI 0.14-0.89 and aOR 0.3, 95%-CI 0.11-0.67, respectively). Conclusions: TB treatment outcomes fell short of the targets set by the World Health Organization of <10% unsuccessful outcomes, indicating a critical need for enhanced management strategies. Tackling loss to follow-up is crucial, especially among MDR-TB patients, including stronger retention activities and improved diagnostic capacities.