1. University Hospital Basel; Institute for Clinical Epidemiology and Biostatistics; Hebelstrasse 10 Basel Switzerland 4031
2. Kantonsspital Basel; Medizinische Universitäts-Poliklinik; Basel Switzerland CH-4031
3. University Hospital Basel; Department of Dermatology; Petersgraben 4 Basel Switzerland 4031
4. University Hospital Basel; Basel Institute for Clinical Epidemiology; Hebelstrasse 10 Basel Switzerland 4031