Smoking and pulmonary tuberculosis treatment failure: a case-control study

Objective To determine the association between smoking and pulmonary tuberculosis treatment failure. Methods This was a case-control study conducted at the Brazilian Institute for Tuberculosis Research in the city of Salvador, Brazil, between 2007 and 2015. We evaluated 284 patients treated for pulmonary tuberculosis, comparing 50 cases of treatment failure with 234 control cases in which the final outcome was cure. Results Treatment failure was attributed to smoking and age rather than to gender, income, level of education, alcohol consumption, or marital status. Therefore, even after adjustment for age, the risk of treatment failure was 2.1 times (95% CI: 1.1-4.1) higher among the patients with a history of smoking. In addition, being over 50 years of age was found to increase the likelihood of treatment failure by 2.8 times (95% CI: 1.4-6.0). Conclusions Smoking and aging are both associated with pulmonary tuberculosis treatment failure. Therefore, as part of a tuberculosis control program, health personnel should be prepared to offer strategies to promote smoking cessation and should be more careful with older patients.