Delirium in older persons.

N Engl J Med 2006;354:1157-65. Copyright © 2006 Massachusetts Medical Society. Delirium, an acute decline in attention and cognition, is a common, life-threatening, and potentially preventable clinical syndrome among persons who are 65 years of age or older. The development of delirium often initiates a cascade of events culminating in the loss of independence, an increased risk of morbidity and mortality, and increased health care costs.1-6 Delirium in hospitalized older patients has assumed particular importance because the care of such patients accounts for more than 49 percent of all hospital days.7 Delirium complicates hospital stays for at least 20 percent of the 12.5 million patients 65 years of age or older who are hospitalized each year and increases hospital costs by $2,500 per patient,8-10 so that about $6.9 billion (value in U.S. dollars in 2004) of Medicare hospital expenditures are attributable to delirium. Substantial additional costs accrue after hospital discharge because of the need for institutionalization, rehabilitation services, formal home health care, and informal caregiving. This report examines current clinical practice in delirium, identifies areas of controversy, and highlights areas for future research.