Association between smoking status, other factors and tuberculosis treatment failure in Morocco

BACKGROUND: The association between smoking and tuberculosis (TB) treatment failure has not yet been assessed in Morocco. OBJECTIVE: To evaluate the impact of smoking on the failure rate of patients with TB. METHODS: A cohort of 727 new TB cases was followed between 2004 and 2009. Socio-demographic measurements and smoking status were collected by questionnaire. Treatment failure was defined according to international guidelines. Univariate analyses were used to assess associations of treatment failure with smoking status and demographic characteristics. Multivariate logistic regression was used to adjust for potential confounding. RESULTS: The patients' mean age was 35.0 +/- 13.2 years. The monthly household income was <(sic)180 for 71.4% of the patients. The rate of treatment failure was 6.9%. Failure was significantly higher among smokers (9.1% vs. 4.5%; P < 0.01), alcohol drinkers (18.5% vs. 4.9%; P < 0.01), and those with a monthly income of <(sic)180 (8.4% vs. 3.3%; P < 0.01). After adjusting for confounding variables, smoking and low income remained significantly associated with treatment failure (adjusted OR 2.25, 95%CI 1.06-4.76, and 3.23, 95%CI 1.12-9.32). CONCLUSION: Smoking is associated with TB treatment failure in Morocco. Anti-smoking interventions should be incorporated into current TB case management.