Association between gait speed and errors on the Clock Drawing Test in older adults with mild cognitive impairment

Individuals with mild cognitive impairment (MCI) often make qualitative errors on the Clock Drawing Test (CDT), and these errors are reported to be associated with lower scores on neuropsychological assessments. Gait speed is also closely associated with cognitive dysfunction. However, the association between CDT errors and gait speed has not been investigated in individuals with MCI. Therefore, in this study, we explored the association between gait speed and qualitative errors on the CDT. Participants were 196 outpatients at a memory clinic with a clinical dementia rating of 0.5. The CDT was evaluated using the method of Cahn et al. The participants were divided into tertiles of normal and maximum gait speeds. The CDT error types of stimulus-bound response, conceptual deficit (CD), and planning deficit were found in 24.5%, 29.6%, and 30.1% of the participants, respectively. CD was found in 43.6% of the slowest tertile of maximum gait and in 22.2% of the fastest tertile. Multiple linear regression analysis gait speeds as objective continuous variables revealed that CD was significantly negatively associated with maximum gait, but not with normal gait. No other error types were associated with gait speeds. Only CD type error on the CDT was negatively associated with maximum gait speed, but not normal gait speed in the current study. The association between the qualitative error on the CDT and gait speed provides further basis of the clinical importance of qualitative assessments of CDT.