See table 1, section 3.1 of SIGN 157  (Overview of delirium assessment tools)

General and community settings

There are many delirium tools.  These have different uses according to setting and application.  In clinical practice in general settings there are two main categories of tools:

1. tools on first presentation and

2. tools for repeated use.

1. Tools on first presentation of the patient

For example, at front door, or new ward admission, in transitions of care, and at any time when delirium is suspected.  Tools in this category include the 4AT, the CAM, and the bCAM.18,20,22,24,30,33. These tools involve bedside assessment with brief cognitive tests and questions to the patient.

2. Tools for repeated use to monitor for new onset delirium These tools mostly involve observation, for example a member of staff noticing that a person has developed new onset drowsiness or confusion.  Tools in this category include NEWS 2 (the New Confusion item), the Single Question in Delirium (SQiD),20 and the Delirium Observation Scale.28,29,30  Monitoring tools, if positive, usually require a further test such as the 4AT to help determine if the patient has delirium.
Intensive Care Unit

There are two main recommended tools: the Confusion Assessment Method for the ICU (CAM-ICU) 19,22,30,31 and the Intensive Care Delirium Screening Checklist (ICDSC).19,31  Both can be used for detection and monitoring.  The CAM-ICU is shorter.  The ICDSC provides a severity score.