Psychometric properties of the Montreal Cognitive Assessment (MoCA) in healthy participants aged 18-70.

Objectives: The Montreal Cognitive Assessment (MoCA) is a cognitive screen, available in three alternate versions. Aims of the current study were to examine the effects of age, education and intelligence on MoCA performance and to determine the alternate-form equivalence and test-retest reliability of the MoCA, in a group of healthy participants.Method: In 210 participants, two MoCA versions and an estimator for premorbid intelligence were administered at two time points.Results: Age, education and estimated premorbid intelligence correlated significantly with the total score (MoCA-TS) and the Memory Index Score (MoCA-MIS). Systematic differences between MoCA version 7.1 and alternate versions 7.2 and 7.3 were only found for the items animal naming, abstract reasoning and sentence repetition. Test-retest reliability of the MoCA-TS was good between 7.1 and 7.2 (ICC: 0.64) and excellent between 7.1 and 7.3 (ICC: 0.82). For the MoCA-MIS, coefficients were poor (ICC: 0.32) to fair (ICC: 0.48), respectively.Conclusion: Adequate norms are needed that take the effects of age, education and intelligence on MoCA performance into account. All three MoCA versions are largely equivalent based on MoCA-TS and the test-retest reliabilities show that this score is suitable to monitor cognitive change over time. Comparisons of the domain-specific scores should be interpreted with caution.Key pointsThe MoCA total score is a reliable cognitive measure.All three MoCA versions are largely equivalent.Age, education and intelligence are predictors of MoCA performance in healthy participants.Future studies should focus on collecting normative data for age, education and intelligence for use in clinical practice.