1. Department of Medical Education, West Virginia University School of Medicine , Morgantown, WV , USA
2. West Virginia University School of Medicine , Morgantown, WV , USA
3. Department of Medicine , University of Minnesota Medical School , Minneapolis, MN , USA
4. Department of Pediatrics , University of Minnesota Medical School , 420 Delaware St SE, MMC 741 , Minneapolis, MN 55455 , USA