A systematic review of the association between pulmonary tuberculosis and the development of chronic airflow obstruction in adults.

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a major public health concern, accounting for 3 million deaths annually, 90% of which occur in low- and middle-income countries. Pulmonary tuberculosis (PTB) as a contributory factor in the aetiology of COPD is under debate, with most epidemiologic evidence suggesting a positive association. OBJECTIVES To compile a systematic review of evidence for an association between PTB and the development of chronic airflow obstruction (CAO). METHODS We performed a systematic review of original English-language, peer-reviewed literature using the PubMed/MEDLINE database. CAO was defined by spirometry [FEV1:FVC ratio <0.70 or <LLN (lower limit of normal) for age]. RESULTS Nineteen studies (1 case series, 3 case-control studies, 4 cohort studies, 8 single-centre cross-sectional studies and 3 multi-centre cross-sectional studies) met the eligibility criteria. All but 2 reported a positive association between PTB and CAO. Three of 4 large population-based surveys (n = 4,291-8,066) confirmed a significant association between PTB and CAO (OR 1.37 - 2.94). A formal meta-analysis was not possible owing to marked heterogeneity between studies. CONCLUSIONS This systematic review confirms evidence for a positive association between a past history of tuberculosis and the presence of CAO. The association is independent of cigarette smoking. Causality is likely but cannot be assumed.