ASSOCIATION BETWEEN CIGARETTE SMOKING AND PULMONARY TUBERCULOSIS

Objectives: To determine the association between cigarette smoking and pulmonary tuberculosis. Methodology: In this retrospective study which was carried out in Razi hospital, in Ahvaz a city southwest Iran, medical charts of patients with tuberculosis between 2005 and 2007 were reviewed. Sixty one patients aged 15-96 years with documented pulmonary tuberculosis (smear positive) were selected as cases and 122 age and sex matched persons without tuberculosis (patients hospitalized in surgery and orthopedic wards) were selected randomly as controls. Data on smoking status, quantity of cigarette smoked, and duration of smoking was collected from medical charts. The data in the two groups were statistically compared with SPSS version 16. The chi square test was used to compare the frequency of cigarette smoking in two groups. Ninety-five percent confidence intervals were calculated when appropriate. Differences with a P value of <0.05 were considered significant. Results: Of total 61 case, 42 (68.9%) were smoker, while, of total 122 controls 22(18%) were smoker. The estimated odds ratio ( OR) of the relation between smoking and tuberculosis was 10.1 [(95% confidence interval (CI) 4.3 to 23.5), P<0.001]. The mean of pocket-year of smoked cigarette (20/pocket) in cases and controls were 15.9 +/- 13.7 and 13.5 +/- 9.1, respectively (P=0.5). Conclusion: This study showed that pulmonary tuberculosis is associated to cigarette smoking. The association is not dose-dependent. Smoking may be a risk factor for TB acquisition