James L. Rudolph, MD, SM, Division of Aging, Brigham and Women's Hospital and the Boston VA Geriatric Research, Education, and Clinical Center, Boston, MA.

Edward R. Marcantonio, MD, SM, Hebrew Rehabilitation Center for Aged and Beth Israel Deaconess Medical Center, Boston, MA.

Delirium is a common syndrome in hospitalized older patients that is frequently undiagnosed by health care professionals. This is particularly troubling because delirium is associated with poor outcomes such as increased nursing home placement, nosocomial infections and increased mortality. Criteria for the diagnosis of delirium are validated, reliable and can readily be applied to patients by health care professionals. Solid evidence exists that delirium can be prevented with educated prescribing of medications, practical in-hospital interventions and geriatric consultation.
Key words: delirium, differential diagnosis, prevention, Confusion Assessment Method.