Normative data for the Clock Drawing Test for French-Quebec mid- and older aged healthy adults.

OBJECTIVE

The Clock Drawing Test (CDT) is frequently used to screen for cognitive impairment, however, normative data for Rouleau et al.'s scoring system are scarce. The present study aims to provide norms for Rouleau et al.'s scoring system that are tailored to Quebec French-speaking mid- and older aged healthy adults.

METHODS

Six researchers from various research centers across the Province of Quebec (Canada) sent anonymous data for 593 (391 women) healthy community-dwelling volunteers (age range: 43-93 years; education range: 5-23 years) who completed the CDT 'drawing on command' version. This command version (setting the clock hands to 11:10, without a pre-drawn circle) was administrated as part of a more extensive neuropsychological assessment, or along with cognitive screening instruments. Each drawn clock was scored according to the quantitative criteria set by Rouleau et al.'s scoring system.

RESULTS

CDT scores were significantly correlated with age (r(592) = -.132, p = .001) and years of education (r(592) = .116, p = .005), but not with sex (r(592) = .065, p = .112). Since data were skewed towards higher test scores, the percentiles method was used for analysis. Percentile ranks stratified by age and education are presented.

CONCLUSION

These normative data for Rouleau et al.'s scoring system will contribute towards adequately screening for cognitive decline in Quebec French-speaking healthy adults, by also taking into account individual characteristics such as age and education.