Types of Delirium Assessments

Patient-based assessments require the provider to perform cognitive testing at the patient’s bedside, which can range from asking patients to recite the months backwards, answer yes or no questions (eg, Does a stone float on water?), or answer questions about orientation (eg, What is today’s date?). The advantage of these assessments is that they potentially achieve higher diagnostic accuracy compared with other approaches. The disadvantage is that the provider must conduct additional cognitive testing, which takes time (up to 5 minutes). Some patient-based assessments require extensive training because they rely on raters’ subjective clinical impressions to determine the presence or absence of delirium’s features. This review includes the Confusion Assessment Method (CAM) and its derivatives (brief CAM [bCAM], CAM for the Intensive Care Unit [CAM-ICU], and 3D-CAM), 4AT, months of the year backwards, and Delirium Triage Screen (DTS).

Proxy-based assessments ask family members or caregivers about the patient’s mental status. The advantage is that these assessments do not place an additional burden on the patient. The disadvantages are, in general, that they have poorer diagnostic accuracy than patient-based assessments and that proxies are not always present with the patient in the ED. This review includes the Single Question in Delirium (SQiD).

Observational assessments use provider observations to determine the presence or absence of delirium. The advantage is that these assessments can be performed by observing the patient during routine clinical care. Therefore, these assessments do not require additional patient interaction or cognitive testing. The disadvantage is that they generally have lower diagnostic accuracies than patient-based assessments. Because these assessments require clinical judgment, they may require training for the rater to reliably detect delirium features. Some assessments (eg, DOSS, NuDESc) are based on observations over an 8- to 12-hour shift and are not feasible for the ED setting. This review includes the Richmond Agitation Sedation Scale (RASS) and modified RASS (mRASS).