Neda Izadi1, Siamak Sabour2. 1. Safety Promotion and Injury Prevention Research Center, Department of Clinical Epidemiology, School of Health, Shahid Beheshti University of Medical Sciences, Chamran Highway, Velenjak, Daneshjoo Blvd, Tehran, 198353-5511, Islamic Republic of Iran. 2. Safety Promotion and Injury Prevention Research Center, Department of Clinical Epidemiology, School of Health, Shahid Beheshti University of Medical Sciences, Chamran Highway, Velenjak, Daneshjoo Blvd, Tehran, 198353-5511, Islamic Republic of Iran. s.sabour@sbmu.ac.ir.