Assessing Treatment Trajectories in Drug-Resistant TB Using Survival Analysis: Evidence from the Rural Eastern Cape

Background: Drug-resistant tuberculosis (DR-TB) remains a critical public health challenge in South Africa, particularly in rural areas with high HIV prevalence. This study aimed to evaluate treatment outcomes and identify risk factors associated with unfavourable outcomes among DR-TB patients in the rural Eastern Cape using survival analysis. Methods: A retrospective cohort study was conducted using data from 323 patients diagnosed with DR-TB and treated between February 2018 and December 2021. Patient demographics, clinical characteristics, and treatment outcomes were extracted from medical records. Kaplan-Meier survival estimates were used to analyse time-to-event data, and Cox proportional hazards regression was used to identify predictors of treatment outcomes. Variables with p < 0.1 in univariate analysis were included in the multivariate model; statistical significance was set at p < 0.05. Results: The median treatment duration was 10 months (IQR: 9–11). The overall cure rate was 36.2% (n=117), treatment completion 26.0% (n=84), LTFU 9.0% (n=29), treatment failure 2.2% (n=7), death 9.3% (n=30), and transfer-out 9.3% (n=30); 8.1% (n=26) were still on treatment. HIV co-infection was present in 62% of patients and was associated with higher mortality (86% of deaths) and treatment failure (86%). In multivariate analysis, primary education (HR = 0.393, 95% CI: 0.23–0.68, p = 0.0017) and secondary education (HR = 0.504, 95% CI: 0.31–0.85, p = 0.0103) were protective. Pre-XDR (HR = 0.134, 95% CI: 0.03–0.81, p = 0.034) and XDR-TB (HR = 0.164, 95% CI: 0.03–0.94, p = 0.043) were unexpectedly associated with lower hazard, likely due to early mortality or transfer. HIV-negative status was linked with a higher hazard (HR = 1.735, 95% CI: 1.13–2.66, p = 0.010). Conclusion: Treatment success rates remain suboptimal among DR-TB patients in the rural Eastern Cape. HIV co-infection, prior treatment history, and low education levels were associated with unfavourable outcomes. Survival analysis highlighted critical timeframes for intervention and retention in care. Targeted support for younger patients, males, and HIV-positive individuals is essential to improve DR-TB treatment outcomes in high-burden rural settings.