1. Department of Epidemiology; School of Public Health; Arak University of Medical Sciences; Arak Iran
2. Department of Epidemiology and Biostatistics; School of Public Health; Knowledge Utilization Research Center; Tehran University of Medical Sciences; Tehran Iran
3. Department of Epidemiology and Biostatistics; School of Public Health; Tehran University of Medical Sciences; Tehran Iran
4. University at Buffalo; Jacobs School of Medicine and Biomedical Sciences; Buffalo NY USA
5. Neurology; Jacobs School of Medicine and Biomedical Science; University of Buffalo; Buffalo NY USA