Rapid screening of cognitive change in patients with questionable dementia using the Memory Impairment Screen and the Isaacs Set Test

Abstract

Objectives: To assess the efficacy of combining the Memory Impairment Screen (MIS) and the Isaacs Set Test (IST) in predicting short-term development of dementia in a group of people with questionable dementia (QD) at baseline.

Design: Performances of the weighted sum of MIS and IST and the <<or>> rule were compared with each other and with the Mini-Mental State Examination.

Setting: Database of the Regional Network for Diagnostic Aid and Management of Patients with Cognitive Impairment in the Franche-Comté geographical area in France.

Participants: A cohort of 106 patients aged 65 and older with QD were followed up for a mean of 14.9 months (range 6-24 months).

Measurements: Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the combination of these two tests.

Results: The weighted sum had a sensitivity of 0.74 and a specificity of 0.84. The <<or>> rule (MIS<6 or IST<25) had a sensitivity of 0.74 and a specificity of 0.81. When range values were applied, low scores on the MIS and the IST (MIS<6 and IST<25) led to a high probability of dementia, whereas high scores (MIS>7 and IST>29) suggested a high probability of remaining dementia-free in the study follow-up.

Conclusion: This quickly performed tool (5 minutes) is simple to use and score. When including cutscores (MIS<6 or IST<25) or range values, this test could be considered a useful screening procedure for all types of dementias.