The accuracy of bedside attention tests for delirium detection in older outpatients with cognitive impairment

Background

To determine the test accuracy of four observations, three explorations and four short tests commonly used in psychiatric examinations to detect attention disorders related to delirium in older outpatients.

Method

We performed a test accuracy study among 86 older patients referred for cognitive screening to an outpatient clinic of a psychiatric institution. Eleven index tests were applied without knowledge of the reference standard. A geriatrician or psychiatrist blinded to the results of the index tests determined the reference diagnosis with DSM-IV-TR criteria. Observations were lack of adequate/ regular eye-contact, dozing off during conversation, dozing off when not stimulated, and losing the point of story. Explored was lack of concentration during activities, difficulty following conversation, and being easily distracted. Serial 7s, WORLD spelled backward, months of the year backward (MOTYB) and counting back from 20 to 0 were applied. Test accuracy was calculated for the single tests and combinations.

Results

Dozing off during conversation scored high specificity (97.9 %) as did dozing off when not stimulated (97.9 %), but both had low sensitivity (< 27.9 %). Test accuracy of the exploration questions was low. Serial 7s and WORLD spelled backwards had high sensitivity (92.7 %, respectively 80.5 %) but low specificity (< 51.1 % %). The best combination was MOTYB with WORLD spelled backward (sensitivity of 63.4 %, specificity of 77.8 %).

Conclusions

No single observation, exploration or short test of attention was found to have both high sensitivity and specificity. Probably, attention deficits in delirium are best detected with a combination of observations and short tests as part of a comprehensive psychiatric examination.