1. Department of Dermatology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
2. Department of Quality Measurements and Research; Clalit Health Services; Tel-Aviv Israel
3. Department of Dermatology; Medical University of Graz; Graz Austria
4. Department of Dermatovenereology; Third Faculty of Medicine; Charles University and University Hospital of Kralovske Vinohrady; Prague Czech Republic
5. Centro Studi GISED; Fondazione per la Ricerca; Ospedale Maggiore; Bergamo Italy
6. Dermatology Department; Inselspital University Hospital; Bern Switzerland
7. Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
8. Department of Clinical Epidemiology; Biostatistics and Bioinformatics; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
9. Institute for Medical Informatics; Statistics and Documentation; Medical University of Graz; Graz Austria
10. Department of Dermatovenereology; Charles University; First Faculty of Medicine and General University Hospital; Prague Czech Republic
11. Department of Epidemiology; Servizio Sanitario Regionale; Regione Lazio Italy