The Clock Drawing Test: Performance differences between the free-drawn and incomplete-copy versions in patients with MCI and dementia

Abstract

Background: The Clock Drawing Test (CDT) is a brief cognitive screening tool for dementia. Several different presentation formats and scoring methods for the CDT are available in the literature. Objective: In this study we aimed to compare performance on the free-drawn and "incomplete-copy" versions of the CDT using the same short scoring method in Mild Cognitive Impairment (MCI) and dementia patients, and healthy elderly participants. Methods: 90 participants (controlled for age, sex and education) subdivided into control group (n=20), MCI group (n=30) and dementia group (n=40) (Alzheimer's disease - AD=20; Vascular Dementia - VD=20) were recruited for this study. The participants performed the two CDT versions at different times and a blinded neuropsychologist scored the CDTs using the same scoring system. Results: The scores on the free-drawn version were significantly lower than the incomplete-copy version for all groups. The dementia group had significantly lower scores on the incomplete-copy version of the CDT than the control group. MCI patients did not differ significantly from the dementia or control groups. Performance on the free-drawn copy differed significantly among all groups. Conclusion: The free-drawn CDT version is more cognitively demanding and sensitive for detecting mild/early cognitive impairment. Further evaluation of the diagnostic value (accuracy) of the free-drawn CDT in Brazilian MCI patients is needed.

Cognitive screening instruments to identify vascular cognitive impairment: A systematic review

“…The CDT had moderate to high sensitivity but low specificity in separating VaD from controls, depending on the scoring approach used. The CLOX1 free drawing variant, sensitive to executive control and useful in early impairment, showed the highest accuracy (AUC 0.83) of all CDTs in identifying VaD but even when combined with cube drawing had poor accuracy for VMCI (AUC 0.66), similar to other versions of the CDT . This is in keeping with the finding of a recent systematic review and meta‐analysis, albeit that paper did not specifically examine diagnostic accuracy of CDTs in VCI .…”

Smart Textiles for Improved Quality of Life and Cognitive Assessment

“…Prior to the development of these tools the standard way to evaluate if a person had a cognitive impairment was through observation by clinical staff, interviews with specialists, and observation by family or caregivers [ 67 ]. Other tests exist, including memory-based tasks, such as the clock drawing test, where the individual is asked to draw a clock face with a given time [ 68 ], and the Wisconsin Card Sorting Test [ 69 ]. The use of technology has become more prevalent in the process of administering diagnosis tests to patients, e.g., CogState Brief Battery questions [ 56 ].…”

Prognosis of Dementia Using Early Fusion Approach with Digital Clock Drawing and Trail-Making Tests

“…The unprompted free drawing method showed a strong correlation with both MMSE (Royall et al, 1998). Additionally, the free-drawn CDT presented a greater cognitive challenge and was more sensitive to detecting mild or early cognitive impairment than the incompletecopy version, where participants copied a clock face with numbers and set the hands for a specific time (Beber et al, 2016). This study consisted of 20 participants from the control group, 30 from the MCI group and 40 from the dementia group (Alzheimer's disease-AD: 20; Vascular Dementia-VD: 20).…”