Reliability and validity of the Japanese version of the 4A's Test for delirium screening in the elderly patient.

Although many screening tools for delirium are available, delirium is still occasionally overlooked or misdiagnosed. One of the reasons for this is the lack of brief screening tools that do not require specialized training to use. The 4 'A's test (the 4AT) is a validated screening tool for delirium that can be administered in a very short time without specialized training.