1. From the University Medical Center Utrecht, Utrecht; Spaarneziekenhuis, Haarlem; Department of Medical Statistics, Leiden University Medical Centre, Leiden, the Netherlands; Finsen Center, Copenhagen University Hospital; Herlev Amtssygehus, University of Copenhagen, Copenhagen; Roskilde Hospital, Roskilde; Hillerød Hospital, Hillerød; Bispebjerg Hospital and Bristol Myers-Squibb, København, Denmark; and Ospedale San Giovanni, Bellinzona, Switzerland.