Impact of different diagnostic criteria on prognosis of delirium: A prospective study

A 2-year follow-up study was performed to compare the prognosis of delirium defined according to 4 different diagnostic classifications (DSM-III, DSM-III-R, DSM-IV and ICD-10 clinical criteria) among 425 elderly geriatric hospital patients and nursing home residents. The proportion of delirium varied from 24.9% (DSM-IV) to 10.1% (ICD-10). The prognoses were similar particularly according to all DSM classifications: 31.3-36.3% of the delirious patients died within 1 year and 57.8-62.5% within 2 years. The number of subjects diagnosed as delirious according to the ICD-10 was small, and their prognosis did not differ significantly from the others either. The DSM-IV has simplified the criteria of delirium. It identifies new, acutely ill and relatively nondependent subjects as delirious who share the poor prognosis of patients diagnosed with the previous criteria. Copyright (C) 2004 S. Karger AG, Basel.