Rouleau version of the Clock Drawing Test: age- and education-adjusted normative data from a wide Italian sample

Abstract

Abstract Objective: The Clock Drawing Test (CDT) is widely used as a screening tool for discriminating cognitively normal individuals from patients with mild dementia. The aim of present study was to provide normative values for a 10-point quantitative scoring system proposed by Rouleau and colleagues (1992), including CDT total score and subscales score assessing representation of clock face (RC), layout of numbers (LN), and position of hands (PH), in a large sample of Italian healthy individuals. Method: Eight hundred and seventy-two Italian healthy participants (483 women; age range 20–94 years) with educational level from primary school to university underwent CDT and Mini Mental State Examination (MMSE). Results: Multiple linear regression analysis revealed that age and education significantly influenced CDT total score and its subscale scores. Moreover, a significant effect of gender was found only in RC subscale. From the derived linear equation, a correction grid for raw scores was built. Inferential cut-off values were estimated using a non-parametric technique and equivalent scores (ES) were computed. Correlation analysis showed a weakly significant correlation between adjusted CDT total score and adjusted MMSE scores. Conclusions: The present study provided normative data for the Rouleau and colleagues version of CDT in an Italian sample, useful for clinical and research purposes.