Smoking Status and Clinical Outcomes among Patients with Multidrug-Resistant Tuberculosis: A Retrospective Comparative Study in Lahore

Abstract

Background: Multidrug-resistant tuberculosis (MDR-TB) remains a major challenge because treatment is prolonged and clinical outcomes can be unfavorable. Tobacco smoking may adversely affect pulmonary defense, microbiological response, and treatment outcomes. This study examined the clinical profile and outcomes of patients with MDR-TB according to smoking status at a tertiary care hospital in Lahore. Objective: To compare demographic, clinical, diagnostic, and treatment characteristics of MDR-TB patients who were smokers and non-smokers. Methodology: A retrospective comparative study was conducted at Lahore General Hospital using records from January 2018 to December 2022. The final analysis included 272 eligible MDR-TB records. Data on demographic characteristics, previous TB treatment, comorbidities, sputum smear results, smoking status, and treatment outcomes were extracted from hospital records. Descriptive statistics and chi-square tests were used, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistical significance was set at p < 0.05. Results: Of 272 patients, 136 (50.0%) were smokers and 136 (50.0%) were non-smokers. Most patients were aged 31–45 years (42.6%), male (64.0%), and urban residents (62.5%). Previous TB treatment was documented in 77.2% of patients, while 39.7% had at least one recorded comorbidity. Overall treatment success was 58.8%. Treatment success was lower among smokers than non-smokers (50.0% vs. 67.6%; χ² = 8.12, p = 0.004; OR for successful outcome = 0.46, 95% CI: 0.27–0.77). Comorbidities were more frequent among smokers (47.1% vs. 32.4%; χ² = 5.78, p = 0.016), and sputum smear positivity was also higher (88.2% vs. 73.5%; χ² = 9.09, p = 0.003). Conclusion: Within this tertiary-care MDR-TB sample, smoking status was significantly associated with treatment outcome, comorbidity burden, and sputum smear positivity. Because of the retrospective design, these findings indicate associations rather than causation. Smoking cessation support and integrated management of comorbidities may be considered as components of comprehensive MDR-TB care.