Prevalence of tobacco consumption among pulmonary tuberculosis patients and its correlation with tuberculosis incidence: a systematic review and meta-analysis in the Indian context.

Tuberculosis (TB) and tobacco use are two intertwined public health challenges that significantly impact low- and middle-income countries, particularly India, which bears the highest global TB burden. Tobacco use exacerbates TB risk, progression, and treatment outcomes. Despite the established association, research on the prevalence of smoking and smokeless tobacco (SLT) use among pulmonary TB (PTB) patients in India remains limited. This systematic review and meta-analysis aim to estimate the prevalence of smoking and SLT use among PTB patients in India and evaluate the association between tobacco consumption and TB incidence and treatment outcomes. A systematic search was conducted across four databases (PubMed, Embase, Web of Science, and Scopus) for studies published up to September 30, 2024, adhering to PRISMA guidelines. Pooled prevalence estimates were calculated using random-effects models, and subgroup analyses examined variations by gender and treatment stage. Odds ratios (ORs) were used to assess the association between smoking and PTB. Sensitivity analyses and Egger's test were conducted to evaluate heterogeneity and publication bias. A total of 27 studies (n=9593 subjects) were included. The pooled prevalence of smoking among PTB patients was 31% [95% confidence interval (CI): 25-36%], while SLT use was 19% (95% CI: 13-26%). PTB patients were 2.5 times more likely to be smokers than non-TB controls (OR=2.51, 95% CI: 1.36-4.62). Smoking prevalence was highest among newly diagnosed patients (42%) and predominantly observed among males (38%). High heterogeneity (I²>98%) was observed across studies. To conclude, tobacco use is highly prevalent among Indian PTB patients, significantly contributing to disease burden. Integrating tobacco cessation strategies into India's National TB Elimination Program is critical to improving TB outcomes, reducing transmission, and addressing the dual burden of tobacco and TB.