The 3D-CAM is a 3-minute delirium assessment that is also based upon the CAM algorithm and has four features: (1) altered mental status/fluctuating course, (2) inattention, (3) altered level of consciousness, and (4) disorganized thinking. Like the CAM, a patient must be inattentive (cardinal feature of delirium) in order to be 3D-CAM positive. It utilizes both objective measures and clinical observation to determine the presence of inattention and disorganized thinking. For inattention, the patient is asked to repeat a series of 3 numbers backwards, repeat a series of 4 numbers forwards, recite the days of the week backwards, and recite the months of the year backwards. For disorganized thinking, the 3D-CAM asks the patient what the year, day of the week, and place is. In older medical inpatients, the 3D-CAM is 95% sensitive and 94% specific for delirium when performed by trained research assistants (Marcantonio et al. Ann Int Med. 2014).
Additional details of the 3D-CAM can be found at the Hospital Elder Life Program website.