1. University of Cologne, Cologne, Germany,
2. Cochrane Haematological Malignancies Group, Department of Internal Medicine I, University Hospital of Cologne, Cologne, Germany,
3. Cochrane Haematological Malignancies Group, First Department of Internal Medicine, University Hospital of Cologne, Cologne, Germany,
4. University of Bern, Institute of Social and Preventive Medicine, Bern, Switzerland,
5. Division of Medical Sciences, Robert Aitken Institute, Birmingham,
6. Department I of Internal Medicine and Center of Integrated Oncology Cologne Bonn, University of Cologne, Cologne, Germany