Association between Tobacco Smoking and Active Tuberculosis in Taiwan

RATIONALE: Previous case-control studies and a small number of cohort studies in high-risk populations have found an association between tobacco and active tuberculosis, but no cohort studies have been conducted in the general population on this association to date. OBJECTIVES: To investigate the association between tobacco smoking and active tuberculosis in a cohort of a general population. METHODS: 17,699 participants (>or=12 y of age) in Taiwan National Health Interview Survey were followed up from 2001 to 2004. Smoking status and other covariates were measured by an in-person interview at baseline. Incident cases of active tuberculosis were identified from the National Health Insurance database. Multivariate logistic regression was used to estimate the association between smoking status and active tuberculosis, with adjustment for age, sex, alcohol consumption, socioeconomic status, and other covariates. MEASUREMENTS AND MAIN RESULTS: Fifty-seven new cases of active tuberculosis occurred during the 3.3 years of follow-up. Current smoking was associated with an increased risk of active tuberculosis (adjusted odds ratio OR, 1.94; 95% confidence interval, 1.01-3.73). The association was stronger among those less than 65 years of age (adjusted OR, 3.04) than those greater than 65 years of age (adjusted OR, 0.78; P(interaction) = 0.036). We found significant dose-response relations for cigarettes per day (P(trend) = 0.0036), years of smoking (P(trend) = 0.023), and pack-years (P(trend) = 0.0023). CONCLUSIONS: Tobacco smoking was associated with a twofold increased risk of active tuberculosis in a representative cohort of Taiwan's population.