Quantitative and Qualitative Analyses of the Clock Drawing Test in Fall and Non-Fall Patients with Alzheimer's Disease

AIM: The clock drawing test (CDT) is widely used as a visual spatial ability test and screening test for dementia patients. The appearance frequency of qualitative errors obtained through the qualitative analysis of CDT may be related to the participant's falls. The aim of this study was to clarify the difference in the number of people who presented with qualitative errors in the CDT between a fall and non-fall group of patients with Alzheimer's disease (AD). METHODS: The CDT was implemented for 47 patients with AD. A quantitative analysis was conducted, and a qualitative analysis was performed for errors. The patients were divided into two groups based on their history of falls over the past year. The results of the CDT quantitative analysis were tested using the Mann-Whitney U test, and Fisher's exact test was employed to determine the difference in the number of people who presented with error types between the two groups (fall group, non-fall group) in the CDT qualitative analysis. RESULTS: In the quantitative analysis, a significant difference was found for the total scores, with the total CDT score of the fall group (n = 22) significantly lower than that of the non-fall group (n = 25) (p = 0.006, effect size: φ = 0.40). In the qualitative analysis, a significantly higher number of patients in the fall group than in the non-fall group presented with a conceptual deficit (p =0.001, φ = 0.51). No differences were found in the number of patients in the two groups who presented with the other five error types. CONCLUSIONS: These results showed that a lower score in the CDT quantitative analysis might suggest an increased risk of falls. It was also clarified that a larger number of patients in the fall group than in the non-fall group presented with a conceptual deficit of the qualitative error types in the CDT. Therefore, these results suggest that the appearance of a conceptual deficit may be an index for the selection of patients with AD prone to falling when implementing fall prevention measures.