Predictors of treatment outcomes of shorter oral treatment regimen for drug-resistant tuberculosis: A programmatic cohort study

Objectives Drug-resistant tuberculosis (DR-TB) remains a major challenge in tuberculosis control despite the introduction of shorter oral treatment regimens. The outcomes of these regimens are influenced by multiple sociodemographic, clinical, radiological, nutritional, and treatment-related factors. Understanding these determinants is essential for optimizing the treatment success of multidrug-resistant tuberculosis (MDR-TB) under routine programmatic settings. Material and Methods This hospital-based ambispective (hybrid) observational study was conducted at a nodal DR-TB center under the National Tuberculosis Elimination Programme. A total of 202 rifampicin-resistant and multidrug-resistant pulmonary TB patients who received a shorter oral regimen and whose treatment outcomes were reported between July 2023 and November 2024 were included. Treatment outcomes were categorized as favorable (cured or treatment completed) and unfavorable (treatment failure, switch due to additional drug resistance, loss to follow-up, or death). Sociodemographic, clinical, radiological, nutritional, and treatment-related variables were recorded. Data was analyzed using appropriate univariate tests, and multivariable logistic regression was performed to identify independent factors associated with unfavorable outcomes. Results Of the 202 patients, 124 (61.38%) achieved favorable outcomes, while 78 (38.61%) had unfavorable outcomes. Patients with unfavorable outcomes had a significantly higher mean age. Upper lower ( p = 0.012) and Lower socioeconomic status ( p = 0.038), illiteracy ( p = 0.009), rural residence ( p = 0.012), smoking, diabetes mellitus ( p = 0.016), hypertension ( p = 0.034), human immunodeficiency virus (HIV) infection, low body mass index (<18.5 kg/m 2 ) ( p <0.001), anemia, history of prior anti-tubercular treatment ( p = 0.021), advanced radiological disease ( p <0.001), treatment delay exceeding eight weeks ( p <0.001), poor drug compliance, and failure of early sputum conversion were significantly associated with unfavorable outcomes. On multivariable analysis, advanced radiological disease [adjusted odds ratio (AOR) 14.80 (95%CI5.3-41.3)], poor compliance, low body mass index (BMI) [AOR 3.85 (95%CI 2.15-6.90)], treatment delay of >8 weeks [AOR 4.30 (95%CI 1.80-10.30)], prior anti-tubercular treatment [AOR 2.10 (95%CI 1.12-3.94)], smoking, comorbidities, and increasing age emerged as independent factors associated with unfavorable outcomes. Conclusion Outcomes of the shorter oral regimen in DR-TB patients are influenced by a complex interplay of sociodemographic vulnerability, namely increasing age, rural residence, and illiteracy. Disease severity in the form of advanced radiological disease, more bacillary load at initiation of treatment, poor nutritional status, delay in seeking treatment, poor follow-up to review evolving resistance patterns, and sputum culture conversion play an important role in determining treatment outcome. Early diagnosis, timely treatment initiation, nutritional and comorbidity management, and strengthened adherence support for adequate follow-up are crucial to improve treatment success with shorter oral regimens under programmatic conditions.