The 4AT is a simple and short (<2 min) delirium detection tool designed for easy and effective clinical use. It does not require special training.

The 4AT is the most-validated delirium tool in the literature, with >27 diagnostic test accuracy studies involving >5000 patients. It is highly sensitive and specific. The 4AT is now one of the most commonly-used tools in practice globally. It is proven in routine care, with high completion rates, and delirium detection at expected clinical rates.