The cube-copying test is used to assess cognitive function. It is one of the methods used to distinguish healthy older individuals from those with cognitive impairment based on its 3 mm vertex criterion and parallel line errors. We sought to assess how: (1) precisely elderly community-dwelling individuals draw cubes based on two different vertex criteria; and (2) they keep the parallelism of lines.
The cross-sectional design study population comprised 121 adults ((outlier analysis excluded the results of three, resulting in 118 participants) ≥ 65 years (21 men and 100 women) who participated in an annual physical fitness circuit and who lived independently in their communities. We recorded the participants’ ages, years of education, and the scores they obtained in the Japanese version of the Montreal Cognitive Assessment. Participants were instructed to draw the cube as precisely as possible. Cube drawings were assessed based on the correct position of the vertices using 1 and 3 mm criteria and parallel line errors.
Eighty-nine percent of the participants were able to draw vertices within 3 mm distance from the correct position but found it difficult to draw them within 1 mm distance. Using the 3 mm vertex criterion, the mean score for correct vertices was six (out of a maximum of eight). Most of the participants made a maximum of one out of six possible parallel line errors.
Almost 90% of the elderly in our study drew the vertices within 3 mm of the correct position, and the parallel line errors were few. The 3 mm vertex and parallel line criteria by cube-copying seem to be cleared by most community-dwelling elderly. Further research should determine if participants aged ≥85 years with less than 6 years of education show different results.

© 2021 Japanese Psychogeriatric Society.

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