1. Department of Gastroenterology and Hepatology, University Center for Gastrointestinal and Liver Diseases , CH-4031 Basel , Switzerland
2. Division of Endocrinology, Diabetes, and Metabolism, University Hospital Basel , 4031 Basel , Switzerland
3. Division of Endocrinology, Diabetes, and Metabolism, University Department of Medicine , Kantonsspital Aarau, 5001 Aarau , Switzerland
4. Division of General and Emergency Medicine, University Department of Medicine , Kantonsspital Aarau, 5001 Aarau , Switzerland
5. Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School , Boston, Massachusetts , USA
6. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet , 17165 Stockholm , Sweden