Factors associated with smoking among tuberculosis patients in Spain

Background: To determine the prevalence of smoking and analyze associated factors in a cohort of patients diagnosed with tuberculosis (TB) in Spain between 2006 and 2013. Methods: Multicenter, cross-sectional, descriptive, observational study using a national database of TB patients, using logistic regression to calculate odds ratios (OR) and confidence intervals (CI). Results: We analyzed 5,846 cases (62 % men, mean age 39 years, 33 % foreigners). 23.4 % were alcohol abuser, 1.3 % were injected drug users (IDU), 4.6 % were co-infected with HIV, and 7.5 % had a history of TB treatment. 6.6 % and 0. 8 % showed resistance to one and multiple drugs, respectively. The predominant clinical presentation was pulmonary (71 %) with a cavitary radiological pattern in 32.8 % of cases. 82 % of cases were confirmed microbiologically, and 54 % were smear-positive microscopy. 2,300 (39.3 %) patients were smokers. The following factors were associated with smoking: male sex (OR = 2.26; CI: 1.97; 2. 60), Spanish origin (OR = 2.79; CI: 2.40-3.24), alcoholism (OR = 2.85; CI: 2.46; 3.31), IDU (OR = 2.78; CI: 1.48; 5.52), homelessness (OR = 1.99; CI: 1.14-3.57), pulmonary TB (OR = 1.61; CI: 1.16; 2.24), cavitary radiological pattern (OR = 1.99; CI: 1.43; 2.79) and a smear-positive microscopy at the time of diagnosis (OR = 1.39; CI: 1.14; 1.17). Conclusions: The prevalence of smoking among TB patients is high. Smokers with TB have a distinct sociodemographic, clinical, radiological and microbiological profile to non-smokers.