Incremental Validity of Montreal Cognitive Assessment Index Scores in Mild Cognitive Impairment and Alzheimer Disease

Abstract

Background/Aims: The aim of this paper was to evaluate the incremental validity of the Montreal Cognitive Assessment (MoCA) index scores and the MoCA total score in differentiating individuals with normal cognition versus mild cognitive impairment (MCI) or Alzheimer disease (AD). Methods: Effect sizes were calculated for Alzheimer's Disease Neuroimaging Initiative research participants with normal cognition (n = 295), MCI (n = 471), or AD (n = 150). Results: Effect sizes for the total score were large (> 0.80) and exceeded the index scores in differentiating those with MCI versus normal cognition, MCI versus AD, and AD versus normal cognition. A combined score incorporating the Memory, Executive, and Orientation indexes also improved incremental validity for all 3 group comparisons. Conclusion: Administration of the entire MoCA is more informative than the index scores, especially in distinguishing normal cognition versus MCI. A combined score has stronger incremental validity than the individual index scores.