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

## TL;DR

This study finds that nearly 60% of pulmonary tuberculosis patients in Tamil Nadu have impaired lung function after treatment, with prior TB episodes and severe lung damage being key risk factors.

## Contribution

The study identifies specific clinical predictors of lung function impairment in post-TB patients in a regional Indian context.

## Key findings

- 59% of treated pulmonary TB patients showed lung function impairment.
- Restrictive lung patterns were the most common impairment type.
- Previous TB treatment history and radiological severity strongly predict LFI.

## Abstract

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.