1. Department of Epidemiology; Faculty of Health; Ilam University of Medical Sciences; Ilam Iran
2. Managerial Epidemiology Research Center; Department of Public Health; School of Nursing and Midwifery; Maragheh University of Medical Sciences; Maragheh Iran
3. Department of Epidemiology and Biostatistics; School of Public Health; Tehran University of Medical Sciences; Tehran Iran