ADAS-Cog

The Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) is a brief neuropsychological assessment used to assess the severity of cognitive symptoms of dementia. It is one of the most widely used cognitive scales in clinical trials[1] and is considered to be the “gold standard” for assessing antidementia treatments.[2]

The ADAS-Cog is one half of the Alzheimer's Disease Assessment Scale (ADAS), which also contains a non-cognitive subscale (ADAS-Noncog), which includes 10 tasks which assess mood and behavioural changes which may occur in Alzheimer's disease and other forms of dementia.[2]

The ADAS-Cog consists of 11 tasks:

  • Word Recall Task
  • Naming Objects and Fingers
  • Following Commands
  • Constructional Praxis
  • Ideational Praxis
  • Orientation
  • Word Recognition Task
  • Remembering Test Directions
  • Spoken Language
  • Comprehension
  • Word-Finding Difficulty

Different versions

Since its original creation in 1980s there have been many alternate versions of the ADAS-Cog created for various reasons. A review found 31 modified versions of the ADAS-Cog,[2] these include:

  • ADAS-Cog-IRT: Uses the standard 11 items from the ADAS-Cog but calculates the score based on item response theory. Using this method each question in the test is given a different value based on the difficulty, which is determined by how frequently it is answered correctly or incorrectly by a large reference group of participants.[3]
  • ADAS-Cog Plus: Developed to be more responsive to the early stage deficits seen is mild cognitive impairment. It includes the standard ADAS-Cog with additional tests to assess executive function and day-to-day function.[4]
  • VADAS-Cog: The VADAS-Cog is a variant the ADAS-Cog adapted to assess people with vascular dementia. It consists of the standard ADAS-Cog with additional measures for attention, working memory, executive function and verbal fluency.[5]

References

  1. ^ Connor, D. J. & Sabbagh, M. N. (2008). "Administration and Scoring Variance on the ADAS-Cog". Journal of Alzheimer's Disease. 15 (3): 461–464. doi:10.3233/JAD-2008-15312. PMC 2727511.
  2. ^ a b c Kueper, J. K.; Speechley, M. & Montero-Odasso, M. (2018). "The Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog): Modifications and responsiveness in pre-dementia populations. A narrative review". Journal of Alzheimer's Disease. 63 (2): 423–444. doi:10.3233/JAD-1709.
  3. ^ Balsis, S. Unger; A. A., Benge; J. F.; Geraci, L. & Doody, R. S. (2015). "Gaining precision on the Alzheimer's Disease Assessment Scale-cognitive: A comparison of item response theory based scores and total scores". Alzheimer's & Dementia. 8: 288–293. doi:10.1016/j.jalz.2011.05.2409.
  4. ^ Skinner, J.; Carvalho, J. O.; Guy, G. P.; Thames, A.; Zelinski, E.; Crane, P. K. & Gibbons, L. E. (2012). "The Alzheimer's Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-Plus): An expansion of the ADAS-Cog to improve responsiveness in MCI". Brain Imaging and Behavior. 6 (4): 489–501. doi:10.1007/s11682-012-9166-3. PMC 3873823.
  5. ^ Ferris, S. H. (2005). "General measures of cognition". International Psychogeriatrics. 15 (S1): 215–217. doi:10.1017/S1041610203009220.