Predictors of mortality and treatment failure in tuberculosis patients enrolled in the tuberculosis and leprosy program in mainland Tanzania: a retrospective cohort study

Abstract Background Tuberculosis (TB) is a significant global health issue, mainly in developing countries. Despite the progress made in reducing TB rates, adverse treatment outcomes, such as deaths and treatment failures, continue to be a concern. We aimed to determine the treatment failure and death rates, and its predictors, among TB patients in Tanzania from January 2022 to December 2023. Methodology We conducted a cohort study utilizing data from the National Tuberculosis and Leprosy Programme database, focusing on TB patients who began treatment in 2022 and 2023. The Cox proportional hazards model was used to conduct univariate and multivariate analyses. Hazard ratios and their respective 95% confidence intervals were reported. Kaplan–Meier curves were employed to estimate the probabilities of these outcomes over time. A p -value ≤ 0.05 was considered significant. Results The overall death rate and treatment failure rate among participants was 2.76 and 0.11%, respectively. Older adults had significantly increased risk of adverse outcomes, with nearly four times the likelihood of death (AHR 3.62, 95%CI: 3.18–4.11, p < 0.001) and twice the likelihood of treatment failure (AHR 2.25, 95%CI: 1.12–4.52, p = 0.022). Male participants faced a higher risk of both death (AHR 1.10, 95%CI: 1.03–1.17, p = 0.003) and treatment failure (AHR 1.56, 95%CI: 1.12–2.17, p = 0.009) than females. Urban residents had increased risk of death (AHR 1.40, 95%CI: 1.32–1.49, p < 0.001) and treatment failure (AHR 1.46, 95%CI: 1.08–1.98, p = 0.014) compared to those in rural areas. Treatment in hospitals was associated with worse outcomes, including almost twice the risk of death (AHR 1.71, 95%CI: 1.57–1.86, p < 0.001) and a higher likelihood of treatment failure (AHR 1.49, 95%CI: 1.01–2.20, p = 0.042). Most deaths occurred within the first two months of treatment, whereas treatment failures peaked at six months. Conclusion The study revealed significant differences in death and treatment failure rates based on patients’ characteristics, with higher risks observed in older adults, males, urban residents, treatment at higher-level facilities, having pulmonary TB, TB/HIV co-infection, retreatment, being treated under Facility DOT, and being referred through other referral types other than self-referral, CTC referral and community referrals. The findings emphasize the need for targeted efforts to improve TB outcomes.