We recently completed an audit on cognitive testing used in routine practice within our Older People Community Mental Health Team in East Dorset, U.K. We measured the frequency of use of the Addenbrooke's Cognitive Examination (ACE) following its introduction as the baseline test for cognition, comparing it to the Mini-mental State Examination (MMSE) (Folstein et al., Reference Folstein, Folstein and McHugh1975).
Published research has shown that the ACE is a better discriminator of dementia than the MMSE, offering greater sensitivity (82%) and equal specificity (96%) for dementia at a cut-off of 83, compared to the MMSE at a cut-off of 24 which has a sensitivity of 52% and specificity of 96% at this score (Mathuranath et al. (Reference Mathuranath, Nestor, Berrios, Rakowicz and Hodges2000).
One of the most interesting and important findings on completion of the audit was that there was an increase in the percentage of cases that showed a disparity of scores (i.e. of significant cognitive impairment when the ACE was compared to the MMSE) between 2005 (17%) and 2006 (36%) when the audit was repeated. That is to say, these cases would have had a “normal” MMSE (a score of 24 or greater), but an abnormal ACE score (a score of 83 or less).
More importantly, these cases could have slipped through the screening assessment for dementia on the basis of their MMSE score alone if no other deficit of functioning was found.
Although the ACE does take a little longer than the MMSE to administer, which may affect compliance rates with this tool, we feel that this is offset by obtaining greater detail in a variety of cognitive domains, such as executive functioning, anterograde memory, episodic memory, speech and language deficits, which the MMSE does not do. We feel justified in using the ACE as a primary tool for cognitive assessments.
