Prevention of delirium in hospitalized older patients: risk factors and targeted intervention strategies

Delirium is a common, costly, and potentially devastating condition for hos pitalized older patients. Delirium is a multifactorial syndrome, involving the inter-relationship between patient vulnerability, or predisposing facto rs at admission, and noxious insults or precipitating factors during hospit alization. Through a series of studies, we first identified significant pre disposing factors for delirium, including vision impairment, severe illness , cognitive impairment, and dehydration. Subsequently, significant precipit ating factors were identified, including physical restraint use, malnutriti on, adding more than three drugs, bladder catheter use, and any iatrogenic event. Through targeting preventive strategies towards six identified risk factors in a controlled clinical trial, we were successful in the primary p revention of delirium. In 852 subjects, the incidence of delirium was signi ficantly reduced in the intervention group compared with usual care (9.9% v s 15.0%, matched odds ratio: 0.60; 95% confidence interval: 0.39-0.92). The total number of days and episodes of delirium were also significantly redu ced in the intervention group. Based on this work, evidence-based recommend ations for delirium prevention are proposed. While not all cases of deliriu m will be preventable with this approach, unifying medical and epidemiologi cal approaches to delirium represents a key advance essential to reducing t he high morbidity and mortality associated with delirium in the older popul ation.