American Hospital Association
Health Research & Educational Trust

Iatrogenic Delirium


The Diagnostic and Statistical Manual of Mental Disorders officially defines delirium as “a disturbance of consciousness with inattention accompanied by a change in cognition or perceptual disturbance that develops over a short period of time (hours to days) and fluctuates over time” (APA, 2000). Delirium often presents as a result of acute medical illness or medication; however delirium in most patients is likely to have multiple causes, though these causes are often very difficult to determine with clinical precision (Fong, Tulebaev & Inouye, 2009). Delirium may be the most common acute disorder affecting adults in general hospitals, affecting 10-20 percent of all hospitalized adults, 14-56 percent of elderly hospitalized patients and up to 80 percent of intensive care unit patients (Fong, Tulebaev & Inouye, 2009; Inouye, 1998).

Delirium increases the risk of longer stays in the hospital and death or long-term cognitive impairment for up to one year after discharge (Pandharipande et al., 2013; Leslie et al., 2005). The increased stays and higher levels of care required for patients diagnosed with delirium results in two and a half times greater costs per day than patients without delirium (Leslie et al., 2008). Delirium does not end at discharge, but continues to affect the patient and their caregivers for years to come through functional decline, higher health care costs and increased morbidity and/or mortality (Francis & Kapoor, 1992). Learn more about delirium’s impacts on patients and their families from Marie.


20 percent reduction in Iatrogenic Delirium Events by 2019.

Partnership for Patients (PfP) Goal