Innovative Black Box: Edinburgh Delirium Test Box

Edinburgh Delirium Test Box

So it’s been a  while since I’ve posted about the Edinburgh Delirium Test Box (EDTB). There was a poster presentation by the researchers in the Edinburgh Delirium Research Group at the June 2011 American Delirium Society (ADS) inaugural meeting in Indianapolis, which I was unable to attend, unfortunately. The poster shows new test data from the group. Background information from one of my earlier posts is excerpted below:

…it’s a computerized neuropsychological testing device and it’s a custom job built for the purpose of diagnosing delirium. Eight novel tasks measuring sustained visual attention were administered to 20 patients with delirium using the EDTB and their performance was compared with that of 18 patients with Alzheimer’s dementia and 20 cognitively normal patients of similar age [1]. The researchers administered 8 tests but clinically you could get away with one brief test to assess delirium. The EDTB could separate delirious from demented and normal control patients in that delirious patients did much more poorly on tasks of sustained visual attention than either of the other two groups. The EDTB is portable and looks promising as way of eliminating most of the clinical judgment calls on diagnoses of delirium. It was compared against a complex scoring system of delirium which included the CAM and another delirium instrument, the Memorial Delirium Assessment Scale (MDAS). All 8 of the sustained attention tasks showed either good or excellent ability to discriminate delirium from dementia. The procedures for administering the tasks are simple and standardized and could be done by a nurse. Larger scale validation studies are in progress.

You can read the entire post at shortlink http://wp.me/p1glcu-k0.

Many thanks to Dr. Alasdair MacLullich, Professor of Geriatric Medicine with the Edinburgh Delirium Research Group at the University of Edinburgh for the updated information about the EDTB. Since the slide is a bit difficult to reproduce in this post, a few words to clarify:

The research group identifies inattention as a core feature of delirium and point out that few objective measures exist. The goal was to do an exploratory study to further validate the use of one EDTB task, sustained visual attention with distraction, to diagnose delirium. The setting and population were in the Orthopedic Trauma Unit at University Teaching Hospital with elderly patients with acute hip fracture.

Methods

  • 108 patients assessed for delirium (CAM and DRS R-98) pre-operatively and up to six further times over 2 weeks
  • Sustained visual attention task performed, taking 4-5 minutes
  • Participants asked to count white lights on a panel, and ignore red distractor lights
  • Six series of white lights shown
  • Responses documented as correct or incorrect for each count (score 0-6)
  • Group comparisons made with Mann-Whitney U, and Spearman’s Rho correlation between DRS R-98 and EDTB score

The results showed an overall rate of delirium of about 42%. The EDTB score was lower in cases than controls on each assessment day, and correlated negatively and significantly with DRS R-98.

In the discussion section, the authors conclude that the EDTB task sustained visual attention with distractors performed well in detecting delirium in elderly patients, and that it might be useful longitudinally for objective monitoring of the severity of attentional deficits in delirium. Of course, further study is required and the group is conducting a larger validation study, which may be finished in June 2012 and which is using an updated version of the EDTB.

So there you have it, the update on the Edinburgh group’s little black box with kudos to Alasdair MacLullich et al for their research. Bang.

1. Brown, L. J., C. Fordyce, et al. (2010). “Detecting deficits of sustained visual attention in delirium.” Journal of neurology, neurosurgery, and psychiatry.
Background Inattention is a core clinical feature of delirium and yet the particular aspects of attentional impairment associated with this feature are poorly understood. Objective methods for assessing inattention are also lacking. A new set of computerised tests of attentional deficits designed for use in patients with delirium have been developed. Test performances in patients with delirium, dementia and cognitively normal controls are compared. Methods Eight novel tasks measuring sustained visual attention were administered to 20 older patients with delirium using the Edinburgh Delirium Test Box, a purpose built, computerised neuropsychological testing device. Comparison groups of 18 patients with Alzheimer’s dementia and 20 cognitively normal patients of similar age were also assessed. Delirium was diagnosed using the Confusion Assessment Method. General cognitive impairment was measured using the Mini-Mental State Examination. Results Patients with delirium had significantly lower scores than both comparison groups on all sustained attention tasks (p values from 0.003 to <0.001). Performance of the dementia patients generally did not differ from the cognitively normal group. Receiver operating characteristic analyses indicated that all tasks showed good or excellent accuracy for discriminating between delirium and dementia (AUC values 0.80-0.94), and between delirium and cognitively normal (AUC values 0.89-0.99) patients. Conclusions Patients with delirium showed marked deficits in sustained visual attention, as measured by objective neuropsychological testing. These attentional deficits were mainly mild or absent in patients with dementia and in cognitively normal controls. Objective testing of sustained visual attention has promising utility in detecting delirium, and in discriminating delirium from dementia.

2. Hall, R. J., M. Allerhand, et al. (2011). Validity of an objective test of sustained visual attention with distractors in detecting delirium. American Delirium Society Inaugural Meeting, June 5-7, 2011. Indianapolis, Indiana.