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

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 <> 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 <> 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.