Clock drawing in the Montreal Cognitive Assessment: recommendations for dementia assessment

Clock drawing is part of the Montreal Cognitive Assessment (MoCA) test but may have administration and scoring limitations. We assessed (1) the reliability of the MoCA clock criteria relative to a published error scoring approach, (2) whether command-only administration could distinguish dementia from cognitively intact individuals and (3) the value of adding a clock copy condition to the MoCA.

Three novice raters and clocks from dementia and control participants were used to assess the 3 aims.

MoCA interrater and intrarater reliability were low (i.e. intraclass correlation coefficient = 0.12-0.31) and required repeat training. Clocks drawn to command classified dementia at chance. Inclusion of a copy condition demonstrated expected dementia subgroup patterns.

Reliable clock scoring with MoCA criteria requires practice. Supplementing a clock copy to the standard MoCA test (takes <1 min) will improve dementia assessment.