1. Pulmonary Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Tobacco Control Research Center, Iranian Anti-Tobacco Association, Tehran, Iran
2. Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
3. Tobacco Control Research Center, Iranian Anti-Tobacco Association, Tehran, Iran