1. Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
2. School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
3. Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
4. School of Information Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
5. University Hospital Heraklion, Crete, Greece
6. School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA