Factors affecting smear conversion in tuberculosis management

Setting: Inpatient clinic at Ministry of Health Sureyyapasa Chest Diseases and Thoracic Surgery Training and Research Hospital Objective: To identify risk factors associated with persistent sputum positivity at the end of 2 months of direct observed treatment Design: Retrospective cohort study concerning evaluation of medical records of 547 patients with smear positive tuberculosis treated at our clinic from January 2004 to December 2005 Results: Of 547 patients with AFB positive smears, late conversion occurred in 11.9% while early conversion in 88.1%. Males composed 54.7% of the population, 31.9% of the population was ≤25 years old, 37.5% had exposure to tobacco, 15.7% had any drug resistance, 8.9% had co-morbid diabetes mellitus and 16.0% had extensive radiologic involvement. Based on significant association between sputum smear conversion and smoking for more than 20 package/year (