Delirium in elderly patients: an overview of the state of the science.

Delirium is a common and potentially preventable and reversible cause of functional disability, morbidity, mortality, and increased health care use among elderly individuals. Much has been learned about delirium in the past decade. Highlighted in this article are recent advances in the diagnosis of delirium, delirium in long-term care, use of health care resources, outcomes of delirium, etiologies, and interventions to prevent and treat delirium. Suggestions for future research also are proposed.