Background: The Clock Drawing Test (CDT) and Rey–Osterrieth Complex Figure Test (RCFT) are widely used as a part of neuropsychological test batteries to assess cognitive function. Our objective was to confirm the prediction accuracies of the RCFT-copy and CDT for cognitive impairment (CI) using the convolutional neural network (CNN) algorithm as a screening tool.
Methods: The CDT and RCFT-copy data were obtained from patients aged 60 to 80 years who had more than 6 years of education. In total, 747 CDT and 980 RCFT-copy figures were utilized. CNN algorithms using TensorFlow (ver. 2.3.0) on the Colab cloud platform (www.colab.research.google.com) were used for preprocessing and modeling. We measured the prediction accuracy of each drawing test 10 times using this dataset: normal cognition (NC) vs. mild impairment of cognition (MI), NC vs. severely impaired cognition (SI), and NC vs. CI (MI +SI).
Results: The accuracy of the CDT was better for differentiating MI (CDT: 78.04±2.75, RCFT-copy: not being trained) and SI from NC (CDT: 91.45±0.83, RCFT-copy: 90.27±1.52); however, the RCFT-copy was better at predicting CI (CDT: 77.37±1.77, RCFT: 83.52±1.41). The accuracy for 3-way classification (NC vs. MI vs. SI) was approximately 71% for both tests; no significant difference was found.
Conclusions: The two drawing tests showed good performance for predicting severe impairment of cognition; however, a drawing test alone is not enough to predict overall CI. There are some limitations to our study: the sample size was small, all participants did not perform both the CDT and RCFT-copy, and only the copy condition of the RCFT was used. Algorithms involving memory performance and longitudinal changes are worth future exploration. These results may contribute to improved home-based healthcare delivery.

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Posted 15 Dec, 2020
Received 15 Feb, 2021
On 15 Feb, 2021
Received 02 Jan, 2021
On 31 Dec, 2020
On 30 Dec, 2020
Invitations sent on 29 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
Posted 15 Dec, 2020
Received 15 Feb, 2021
On 15 Feb, 2021
Received 02 Jan, 2021
On 31 Dec, 2020
On 30 Dec, 2020
Invitations sent on 29 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
On 28 Nov, 2020
Background: The Clock Drawing Test (CDT) and Rey–Osterrieth Complex Figure Test (RCFT) are widely used as a part of neuropsychological test batteries to assess cognitive function. Our objective was to confirm the prediction accuracies of the RCFT-copy and CDT for cognitive impairment (CI) using the convolutional neural network (CNN) algorithm as a screening tool.
Methods: The CDT and RCFT-copy data were obtained from patients aged 60 to 80 years who had more than 6 years of education. In total, 747 CDT and 980 RCFT-copy figures were utilized. CNN algorithms using TensorFlow (ver. 2.3.0) on the Colab cloud platform (www.colab.research.google.com) were used for preprocessing and modeling. We measured the prediction accuracy of each drawing test 10 times using this dataset: normal cognition (NC) vs. mild impairment of cognition (MI), NC vs. severely impaired cognition (SI), and NC vs. CI (MI +SI).
Results: The accuracy of the CDT was better for differentiating MI (CDT: 78.04±2.75, RCFT-copy: not being trained) and SI from NC (CDT: 91.45±0.83, RCFT-copy: 90.27±1.52); however, the RCFT-copy was better at predicting CI (CDT: 77.37±1.77, RCFT: 83.52±1.41). The accuracy for 3-way classification (NC vs. MI vs. SI) was approximately 71% for both tests; no significant difference was found.
Conclusions: The two drawing tests showed good performance for predicting severe impairment of cognition; however, a drawing test alone is not enough to predict overall CI. There are some limitations to our study: the sample size was small, all participants did not perform both the CDT and RCFT-copy, and only the copy condition of the RCFT was used. Algorithms involving memory performance and longitudinal changes are worth future exploration. These results may contribute to improved home-based healthcare delivery.

Figure 1
This is a list of supplementary files associated with this preprint. Click to download.
Loading...