Does a reliable decline in Mini Mental State Examination total score predict dementia? Diagnostic accuracy of two reliable change indices

Abstract

Background/aim: Norms for change in Mini Mental State Examination (MMSE) total score suggest that only a decline of at least 2-4 points indicates a reliable change. However, it is unknown whether change norms (Reliable Change Indices, RCIs) of the MMSE total score are suitable to predict future dementia.

Methods: 554 elderly individuals aged 75 and over without dementia at the first 2 visits were tested with the MMSE at a maximum of 6 visits with 1.5-year intervals. Two different RCIs for change in MMSE score (first to second visit) were computed - one RCI which corrects for practice and one RCI which corrects for regression to the mean. The main outcome measure was the diagnosis of dementia.

Results: During the study, 88 persons developed dementia. RCIs were significantly associated with future dementia diagnosis. The best cutoff for raw change in MMSE total score to predict dementia was -1 point (sensitivity = 48%, specificity = 67%, relative risk = 1.6). With the RCI + regression to the mean, the diagnostic accuracy was moderate (sensitivity = 61%, specificity = 72%, relative risk = 3.2).

Conclusion: A change in MMSE total score is significantly associated with future dementia, but the diagnostic accuracy for dementia prediction is rather low.