1. Erasmus University Medical Center, Rotterdam, The Netherlands;
2. Department Internal Medicine III, University-Hospital, Mainz, Germany;
3. Hôpital Mont Godinne, Yvoir, Belgium;
4. HOVON Data Center and Dept of Trials and Statistics, Erasmus University Medical Center, Rotterdam, The Netherlands;
5. University Medical Center, Maastricht, The Netherlands;
6. University Medical Center, Utrecht, The Netherlands;
7. Hôpital St Luc, Brussels, Belgium;
8. University Hospital, Bonn, Germany;
9. Amsterdam University Medical Center, Amsterdam, The Netherlands;
10. University Medical Center, Groningen, The Netherlands;
11. Hospital Stuivenberg, Antwerp, Belgium;
12. Hospital Heilig Hart, Roeselaere, Belgium;
13. Medisch Spectrum Twente, Enschede, The Netherlands;
14. University Hospital Gasthuisberg, Leuven, Belgium;
15. Department of Internal Medicine III, University Ulm, Ulm, Germany;
16. University Hospital, Basel, Switzerland;
17. Inselspital, Bern, Switzerland; and
18. VU University Medical Center, Amsterdam, The Netherlands