Han JH, et al. - The diagnostic performances of several single question delirium screens were determined. The patient was asked: “Have you had any difficulty thinking clearly lately?” Patient's surrogate was asked: “Is the patient at his or her baseline mental status?” and “Have you noticed the patient's mental status fluctuate throughout the course of the day?” It was noted that in the ED, the patient and surrogate single question delirium assessments might be useful for delirium screening.