Older patients with delirium are at increased risk for prolonged hospitalization, poor outcomes, higher costs and a greater risk for institutionalization. By identifying those at risk early, interventions can be implemented to prevent or minimize the severity of the delirium. Per hospital policy, our geriatric emergency department (ED) screens for delirium by performing a 4AT only if changes in mental status are noted by caregivers or healthcare providers familiar with the patient. We hypothesize this approach underestimates the prevalence of delirium on presentation to the ED, particularly among high-risk older patients. The aim of this study is to determine how many cases of delirium that are present on admission are missed using this traditional approach.
High risk older patients presenting to the ED were identified using an internally devised Electronic Medical Record (EMR) based risk stratification algorithm with known risk factors for delirium including age (>65 years old), polypharmacy (>10 medications), dementia history, sensory impairment and repeat ED visits or hospitalizations (>5 over the preceding year). Of these high-risk patients, 100 patients were randomly selected to undergo a 4AT delirium screen in the ED on presentation, regardless of whether mental status changes were noted in triage. Incidence of delirium and cognitive impairment on presentation using the 4AT score was calculated and contrasted with the traditional approach using the McNemer test to detect any statistical difference.
The average age was 74 years old (65-95 years old), outpatient medication count was 15 (0-40) and average prior ED visits/hospitalizations over the preceding year was 3 (1-68). Seven had a known prior history of dementia, 56 were male and 44 were female. Of the 100 patients screened, 14 scored 4 or above on the 4AT; indicating delirium on arrival. Of these 14, only 3 were detected using the traditional approach. The difference between the number of cases detected by the traditional approach and the EMR based risk stratification method was noted to be significant (p<0.05). 27 of those screened scored 1-3; indicating likely underlying cognitive impairment not meeting criteria for delirium. None of these patients were detected by the traditional method.
All high-risk older patients, as identified by the EMR, should be screened for delirium on presentation to the ED at the time of triage using the 4AT screen or comparable screening test. This screening should not be dependent only on report of acute mental status changes by patient or caregivers. Patients with underlying cognitive impairment who do not screen positive for delirium but score 1-3 on 4AT are likely to benefit from the early implementation of delirium prevention strategies.