The Montreal Cognitive Assessment, MOCA: a brief screening tool for Mild Cognitive Impairment
Nasreddine ZS, Phillips NA, Bédirian V, Charbonneau S, Whitehead V, et al.;
Commented by , 21 Apr 2005
Aim of the study
To develop a 10-minute cognitive screening tool to assist in the detection of mild cognitive impairment (MCI) by primary care practitioners.
Method
This validation study was done in a community clinic and an academic center. The MoCA was administered to 90 healthy controls, 94 subjects with MCI (90 with amnestic MCI, 4 with multiple domains MCI) and 93 patients with mild (MMSE 17 or more) probable Alzheimer’s disease (AD).
The final version of the MoCA used in this study is a one-page 30-point test, including short-term memory recall, executive function tests, sustained attention task, serial subtraction task, digits forward and backward, language tasks, and orientation to time and place.
Results
French and English versions of the MoCA were found to be equivalent. Test-retest reliability was high with less than 1 point variation. Internal consistency was good, with a Cronbach alpha of 0,83. To correct for educational effects, 1 point was added for participants with 12 years of education or less.
Using a cutoff score of 26, the MMSE had a sensitivity of 18% to detect MCI, whereas the MoCA detected 90% of MCI subjects. For the mild AD patients, the sensitivity was 78% and 100% respectively. Specificity was considered as excellent for both screening tests (100% and 87% respectively).
Professor Gauthier's comments
MCI is an intermediate clinical state between normal cognitive aging and dementia. It is being recognized as common and important as a risk factor towards dementia, although it is not yet possible to predict who will progress to functional impairment and how fast. Furthermore many subjects remain at the MCI stage or even revert back to normal over time.
The MoCA is thus a short (10 minutes) user-friendly screening test for subjects with memory complaints who score normal on MMSE (score 26 to 30). Subjects with high performance on the MoCA (scores of 26 to 30) can be reassured, any concomitant medical or psychiatric problem treated, and seen on follow-up on a yearly basis.
Those with abnormal MoCA can be referred to memory clinics or consultants who can perform more detailed clinical, psychometric and brain imaging assessments. The MoCA test is available at www.mocatest.org.