The effects of smoking on treatment outcome in patients newly diagnosed with pulmonary tuberculosis.

SETTING

Smoking is reported to be associated with tuberculosis (TB), but its effect on sputum smear conversion remains a matter for discussion.

OBJECTIVE

To assess the effects of smoking and smoking cessation on treatment outcomes in patients newly diagnosed with TB in Iran.

DESIGN

Newly diagnosed smear-positive TB patients were included in the study. All smokers participated in a smoking cessation programme. Sputum smear status was evaluated at the end of month 2, 5 and 6 of treatment, and smoking status was evaluated at the end of month 2. Differences in smear conversion rates were compared between the three groups, i.e., non-smokers, smokers and quitters.

RESULTS

A total of 183 smokers and 151 non-smokers were included. When smoking cessation was assessed after 2 months, 42.6% (78/183) of the smokers were found to have quit. The cure rate at the end of 6 months, precisely compatible with the conversion rate, was significantly higher among non-smokers (P = 0.004) and quitters at 2 months (P = 0.049) than among persisting smokers (83.4%, 80.8% and 67.6%, respectively).

CONCLUSION

Cure rates in patients newly diagnosed with pulmonary TB were higher in non-smokers and quitters at 2 months than in smokers. Smoking cessation advice should be included in TB control programmes.