Abela A I investigator.; Aebi‐Popp K investigator.; Anagnostopoulos A investigator.; Battegay M investigator.; Bernasconi E investigator.; Braun DL investigator.; Bucher HC investigator.; Calmy A investigator.; Cavassini M investigator.; Ciuffi A investigator.; Dollenmaier G investigator.; Egger ...