1. Shannon School of Business, Cape Breton University, Sydney, NS, Canada
2. Rheumatic Diseases Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
3. Department of Epidemiology and Biostatistics, Faculty of Health Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
4. School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran