Table 1.

Delirium Observation Screening scale [34,35]

	The patient:	Never	Sometimes or always
1	Dozes during conversation or activities	0 points	1 point
2	Is easily distracted by stimuli from the environment	0 points	1 point
3	Maintains attention to conversation or action	1 point	0 points
4	Does not finish questions or answers	0 points	1 point
5	Gives answers which do not fit the question	0 points	1 point
6	Reacts slowly to instructions	0 points	1 point
7	Thinks to be somewhere else	0 points	1 point
8	Knows which part of the day it is	1 point	0 points
9	Remembers recent events	1 point	0 points
10	Is picking, disorderly, restless	0 points	1 point
11	Pulls IV tubes, feeding tubes, catheters etc.	0 points	1 point
12	Gets easily or suddenly emotional (frightened, angry, irritated)	0 points	1 point
13	Sees persons/things as somebody/something else	0 points	1 point

For each of three daily shifts the total score is calculated; the total score per shift is a minimum of 0 and a maximum of 13; the total score for a day is a minimum 0 and a maximum of 39. The DOS scale final score is calculated by dividing the total score for the day by 3; the DOS final score is between 0 and 13

The cut-off point is 3; a DOS scale final score of 3 or more indicates a delirium