Incidence and Risk Factors of Tuberculosis-Associated Chronic Obstructive Pulmonary Disease

Purpose: Chronic obstructive pulmonary disease (COPD) is influenced by multiple factors. Varying prevalences of tuberculosis-associated COPD exist. However, studies on its incidence or risk factors are limited. We evaluated the incidence of tuberculosis-associated COPD and compare the characteristics of patients with and without COPD. Patients and Methods: This multicenter, retrospective cohort study included 351 patients treated with anti-tuberculosis drugs for more than 6 months in four hospitals in Korea, followed for 11 years (132 months). The follow-up duration was divided into quartiles (Q1-Q4) to evaluate the change in the incidence of COPD over time. Clinical data and radiological findings were collected, and the incidence rate ratios were compared using Poisson regression and multivariable logistic regression analysis to identify risk factors. Results: Overall, 71 participants developed tuberculosis-associated COPD, with an overall crude incidence of 20.56/1000 person-years. Patients with tuberculosis-associated COPD were older, more likely to be smokers, and had lower forced expiratory volume in 1 s (FEV1) (L) and lower FEV1/forced vital capacity. The incidence over 132 months was significantly lower than those during follow-up, with an incidence rate ratio of 0.49 (p=0.027). Multivariate analysis revealed that a tuberculosis diagnosis at an older age (adjusted odds ratio [aOR] 1.04; 95% confidence interval [CI]: 1.01–1.07), lower baseline FEV1 <80% (aOR 3.98; 95% CI: 1.92–8.24), smoking (aOR 3.23; 95% CI: 1.14–9.17), and multilobar involvement of tuberculosis (aOR 2.04; 95% CI: 1.08–3.85) were risk factors for tuberculosis-associated COPD. The incidence in the Q4 (>132 months, approximately 11years) was significantly lower than that in the Q1 (18–71 months), with incidence rate ratio of 0.49 (p= 0.027). Conclusion: Older age at tuberculosis diagnosis, lower baseline FEV1 <80%, smoking history, and multilobar involvement were identified as risk factors for tuberculosis-associated COPD. The incidence of tuberculosis-associated COPD decreased 11 years after tuberculosis treatment.