Siamak Sabour1,2. 1. Department of Clinical Epidemiology, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Chamran Highway, Velenjak, Daneshjoo Blvd, 198353-5511, Tehran, Islamic Republic of Iran. s.sabour@sbmu.ac.ir. 2. Safety Promotions and Injury Prevention Research Centre, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. s.sabour@sbmu.ac.ir.