1. University Hospital of Cologne; Cochrane Haematological Malignancies Group, Department I of Internal Medicine; Kerpener Str. 62 Cologne Germany 50924
2. Burbacher Straße 116 Bonn Germany 53129
3. Medical Center - University of Freiburg; Center for Medical Biometry and Medical Informatics; Stefan-Meier-Str. 26 Freiburg Germany D-79104
4. University of Bern; Institute of Social and Preventive Medicine; Finkenhubelweg 11 Bern Switzerland CH-3012
5. University Hospital of Cologne; Department I of Internal Medicine; Kerpener Str. 62 Cologne Germany 50924