Outcomes of long-term treatment regimens in patients with multidrug-resistant tuberculosis (MDR-TB)

Multidrug-resistant tuberculosis (MDR-TB) requires prolonged treatment associated with significant toxicity and high attrition rates. We evaluated treatment outcomes and identified independent predictors of poor prognosis in a large cohort at a national reference center in Turkey.

This retrospective cohort study included 429 patients with rifampicin-resistant (RR-TB) or multidrug-resistant tuberculosis (MDR-TB) treated at Süreyyapaşa Chest Diseases and Thoracic Surgery Training and Research Hospital, Istanbul, between January 2013 and December 2025. Demographic, clinical, microbiological, and chest CT radiological data were collected from medical records. Treatment outcomes were defined according to 2013 WHO criteria and dichotomized into treatment success versus poor outcome (treatment failure, loss to follow-up, or death). Univariate and multivariate binary logistic regression analyses were performed to identify independent predictors of poor treatment outcomes. Statistical analyses were performed using IBM SPSS Statistics v26.0.

The overall treatment success rate was 84.6% (n = 363). Poor outcomes occurred in 15.4% of patients, comprising loss to follow-up (7.9%, n = 34) and death (7.5%, n = 32). Male sex (p = 0.026), foreign nationality (p = 0.006), advanced age (p = 0.001), previously treated cases (p = 0.020), comorbidities (p = 0.037), quinolone resistance (p = 0.003), and adverse drug reactions (p = 0.011) were significantly associated with the overall distribution of treatment outcomes in univariate analysis. Chest CT was available for 205 patients; bronchiectasis (p = 0.004), pleural effusion (p < 0.001), and pleural thickening (p = 0.049) were associated with poor outcomes. In multivariate analysis, comorbidities (OR 5.18, 95% CI 1.46-18.37, p = 0.011) and bronchiectasis on chest CT (OR 3.52, 95% CI 1.14-10.85, p = 0.029) were the only independent predictors of poor treatment outcomes.

The treatment success rate observed in our national reference center cohort compares favorably with published international MDR-TB outcomes. Comorbidities and bronchiectasis-associated structural lung damage independently increase poor outcome risk and warrant intensified clinical monitoring.