Unit 3 – The Delirium Observation Scale

Section 1

Having covered the presentation of mental states in Unit 1 and the risk factors which predispose and precipitate delirium in Unit 2 we will now turn to the use of a clinical tool which can be used to support your clinical decision making about whether or not a person is delirious.  This tool is called the Delirium Observation Scale.

Exercise 1: The DOS Scale:

The patient:
1 Dozes during conversation or activities
2 Is easy distracted by stimuli from the environment
3 Maintains attention to conversation or action
4 Does not finish question or answer
5 Gives answers which do not fit the question
6 Reacts slowly to instructions
7 Thinks he/she is somewhere else
8 Knows which part of the day it is
9 Remembers recent event
10 Is picking, disorderly, restless
11 Pulls IV tubes, feeding tubes, catheters etc.
12 Is easily or suddenly emotional (frightened, angry, irritated)
13 Sees persons/things as somebody/something else

Never = 0 point;
Sometimes or always = 1 point
Items 3, 8 and 9 are rated in reverse

Section 2 – The Delirium Observation Scale (DOS)

The DOS could be completed on any patient who you notice has had a sudden (i.e in the last few hours or days) change in behaviour or cognition.   Anyone who is high risk for delirium based on your admission assessment should be assessed to provide a useful baseline for future assessment.

At the development stage, the DOS Scale was designed with 25 behavioural items that were rated on a 5-point Likert scale. On the basis of studies on geriatric and hip fracture patients, the scale was reduced to 13 items that can be rated as present or absent in less than 5 minutes. A score of 0 is defined as ‘normal behaviour’, meaning absence of behavioural alterations. Three items (3, 8 and 9) are reverse-scored, i.e. ‘normal behaviour’ is rated as ‘always’. The highest total score is 13; the cut-off point is 3. Three or more points indicates a delirium.

Section 3

Next look at the video of Ted on the ward again.  Do the DOS scale on Ted and keep record of your score:

Section 4

The correct score on the DOS scale for Ted is between 7-10 (for this exercise some of the answers are debatable but in practice you would be more certain of answers to question 9, for example, as you would have chance to chat with the patient yourself).

This means according to the DOS Ted is delirious.

Section 5

Next please write a clinical reflection on a patient you have looked after with an altered mental state in the past couple of months:

  • Write a short description of his/her presentation
  • Risk factors
  • Write what assessment was made of that patient’s mental state at the time
  • Having completed Unit 1 and 2 write if you have changed your mind about that patient’s assessment?  / reinforced your original assessment
  • Give reasons for the last answer

Place this reflection in your portfolio.

Section 6

  1. Take a copy of the DOS to your ward and complete 3 assessments of patients over 70 with an altered mental state.
  2. Check your scores with another nurses’ opinion.
  3. Include the findings and a short report in your portfolio.