1. Department of Internal Medicine, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
2. Department of Internal Medicine, Division of Gastroenterology, Wayne State University School of Medicine, Detroit, MI, USA
3. Department of Biostatistics, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
4. Department of Pediatrics, Adolescent and Internal Medicine, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA