1. Student Research Committee, Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran
2. Clinical Research Development Unit, Imam Hossein Hospital, Shahroud University of Medical Sciences, Shahroud, Iran
3. Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran
4. Department of Public Health and Community Medicine, School of Medicine, Tufts University, Tufts, USA
5. School of Allied Medical Sciences, Semnan University of Medical Sciences, Semnan, Iran
6. Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran