The 3-minute Visual Association Test (VAT), which tests associative memory, is a highly sensitive and valuable tool for detecting dementia risk in patients with a small decline on the 30-point Mini-Mental State Examination (MMSE), according to a study published in the Annals of Family Medicine.
Participants in the Prevention of Dementia by Intensive Vascular Care trial (age 70-78 years) were included in this study (n=2690). Investigators evaluated the change in MMSE score over a 2-year period as well as the VAT score at 2 years to determine whether these tests could predict dementia diagnosis in the following 4 to 6 years. Electronic health records provided information on dementia status at 2-year intervals.
A reduction in the total MMSE score of 2 points over a 2-year period was associated with increased odds for developing dementia, according to the logistic regression analysis (odds ratio 3.55; 95% CI, 2.51-5.00). When the VAT score was imperfect (≤5 points) and the MMSE score decreased 1 point over 2 years, there was additional increased odds for developing dementia (odds ratio 9.55; 95% CI, 5.89-15.41). Additionally, the predictive value of a 2- or 3-point MMSE score reduction increased when the VAT score was imperfect. A 1-point reduction on the MMSE score was associated with a doubled risk for dementia if the VAT score was imperfect (12.2%; 95% CI, 7.5%-17.0%).
The small sample size as a result of inclusion of only patients who were tested on the MMSE and VAT assessments at baseline and 2-year follow-up represents a limitation of this study.
Researchers concluded that the VAT “can help to distinguish those at increased risk of developing dementia (requiring counseling, additional examination, or both) from those in whom watchful waiting is justified.”
Jongstra S, van Gool WA, Moll van Charante EP, et al. Improving prediction of dementia in primary care. Ann Fam Med. 2018;16(3):206-210.