The full text of this article hosted at iucr.org is unavailable due to technical difficulties. ORIGINAL ARTICLE Undiagnosed delirium is frequent and difficult to predict: Results from a prevalence survey of a tertiary hospital Peter W. Lange Corresponding Author E-mail address: peter.lange@mh.org.au https://orcid.org/0000-0002-0162-1664 Department of Medicine and Aged Care, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia Correspondence Peter W.