Lung Function Impairment and Its Associated Factors in Pulmonary Tuberculosis Patients Upon Treatment Completion in Madurai District, Tamil Nadu: A Cross-Sectional Study.

Background While effective anti-tuberculosis treatment (ATT) has led to significant reductions in mortality, concerns persist about the potential for persistent lung damage and impaired pulmonary function among survivors. Data on the prevalence and predictors of lung function impairment (LFI) in post-TB patients in Tamil Nadu are limited. This study aims to evaluate the extent of LFI in pulmonary tuberculosis (PTB) patients upon treatment completion. Methods A cross-sectional analytical study was conducted among 132 adult patients aged 18 years and above diagnosed with PTB registered in the government National TB Elimination Program (NTEP) centres, in Madurai district, Tamil Nadu, with smear negative status at completion of standard ATT. Information was obtained on personal habits, respiratory symptoms and co-morbid conditions. A pulmonary function test was done using spirometry. Multiple binary logistic regression analysis was done to find the factors associated with LFI. Results Among the patients, 78 (59%; 95% CI (51% to 67%)) showed LFI. The most common abnormality identified was the restrictive pattern, seen in 72 individuals (55%). Patients with a previous history of anti-tuberculosis treatment (adjusted odds ratio (AOR) 2.4; 95% CI 1.0-5.7; p =0.034)), bilateral lung infiltrates (AOR 7.9; 95% CI: 2.7-23.3; p < 0.001), and ≥4 chest X-ray zones (AOR 11.1 CI 2.9-42.3; p <0.001) were more likely to have LFI. Conclusion LFI is highly prevalent among PTB patients after treatment completion, with previous TB episodes, radiological severity, and bilateral infiltrates being strong predictors. These findings underscore the necessity of post-treatment pulmonary surveillance, spirometry, and pulmonary rehabilitation to be integrated into TB care frameworks in this population.