1. Department of Orthopaedics, Rocky Vista University, College of Osteopathic Medicine, Parker, Colorado
2. Department of Orthopaedics, University of Colorado School of Medicine, Aurora
3. Gastrointestinal Epidemiology Research Center, Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
4. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
5. Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
6. Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
7. Department of Health Policy & Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland