Alternate-form reliability of the German Montreal Cognitive Assessment (MoCA) screening test

Objectives The Montreal Cognitive Assessment (MoCA; Nasreddine et al., JAGS 2005) is a brief measure of global cognitive function used worldwide and validated as a reliable tool for the detection of cognitive impairment in several neurodegenerative diseases and medical conditions. Our objective was to investigate the validity of the German MoCA alternate forms for the purpose of longitudinal clinical and research applications. Methods Two alternate forms were adapted for German using the English versions. The original and one of the two alternate forms were administered within an approximately 60 min interval of a structured clinical interview in pseudo-randomized order to 100 normal elderly controls (NC; mean (SD): age: 66.84 (9.08); education=11.4 (2,9)); 20 patients with mild cognitive impairment (MCI; mean (SD): age: 69.5 (8.21); education=11.29 (2.9)) and 23 patients with Alzheimer's disease (AD; mean (SD): age: 71.35 (8.9); education=10.6 (2.3)). Results Total scores (corrected for education) for the NC group showed no significant differences between the original version (MoCA 1 (mean (SD)): 26 (3)) and the new alternate forms, (MoCA 2: 26.1 (3.2), MoCA 3: 25.5 (2.9). We also found a high correlation between all versions (all r’s >0.6, all p’s=0.01). The order of application showed no effect on total score. Significant differences between patient groups and controls were found for all 3 versions (p>0.001). Total scores for MCI: MoCA 1: 23.1 (2.8), MoCA 2: 22.8 (2.4), MoCA 3: 22.58 (3.4). Total scores for AD: MoCA 1: 16 (4.3), MoCA 2: 16.1 (4.3), MoCA 3: 16 (3.9). Conclusion Our results show strong correlations between all three versions of German MoCA and no significant differences when comparing total scores. All three forms discriminated controls, MCI and AD patients. Therefore, our results show that all three forms can be reliably used in serial cognitive assessment, with special focus in both research and clinical longitudinal approaches. Literatur: Nasreddine, Z. S., Phillips, N. A., Bédirian, V., Charbonneau, S., Whitehead, V., Collin, I., Cummings, J. L., et al. (2005). The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. Journal of the American Geriatrics Society, 53(4), 695–699. doi:10.1111/j.1532-5415.2005.53221.x