Improving the outcomes of delirium in older hospital inpatients.

Delirium is a cognitive disorder characterized by acute onset, fluctuating course and disturbances in consciousness, orientation, memory, thought, perception and behavior (American Psychiatric Association, 2000). It occurs in hyperactive, hypoactive or mixed forms in up to 42% of older hospital inpatients (Siddiqi et al., 2006), many with pre-existing dementia (Fick et al., 2002). Notably, the occurrence of an episode of delirium in older hospital inpatients is associated with many poor outcomes, including increased cognitive impairment and functional disability (Inouye et al., 1998; McCusker et al., 2001), length of hospital stay (O’Keeffe and Lavan, 1997; Inouye et al., 1998), rates of institutionalization (O’Keeffe and Lavan, 1997; Inouye et al., 1998; McCusker et al., 2001) and rates of death (Rockwood et al., 1999; McCusker et al., 2002). Interventions to address these poor outcomes would improve the lives of older people and probably reduce health care costs (Inouye, 2006). To date, however, trials of different interventions (i.e. systematic detection of delirium early in the course of hospitalization, multi-faceted interventions to reduce drug use, manage medical problems optimally, increase family and nursing support and increase sensory cues) have not demonstrated any substantial benefits (Cole, 2004). We propose that the poor outcomes associated with delirium in older hospital inpatients may be related, in large part, to the persistence of delirium in a substantial minority of these patients. Accordingly, interventions to identify this substantial minority and ensure full recovery from delirium may improve the poor outcomes.