The Clock Drawing Test: A Valid Screening Instrument for Dementia Detection in Low-Educated Patients?

Geriatrics, vol. 10, pp. 164

Abstract

Objective: The non-verbal nature of the Clock Drawing Test (CDT) suggests it is a suitable cognitive screening instrument for populations with lower educational levels and/or language barriers. This study evaluates whether the CDT is a valid screening instrument for low-educated patients and includes a qualitative analysis of CDT errors. Method: A total of 503 participants were included, divided into four groups (dementia, MCI, no cognitive impairment, and other diagnosis), based on a clinical diagnosis by a geriatrician. Educational levels were categorized into four groups: no education and low, middle, and high education. CDT scores were assessed using the seven-point scoring system (Freedman), and two cutoff points were evaluated. Results: Results showed that in all education categories, the dementia group scored significantly lower on the CDT compared to the non-dementia group. The difference was smallest in participants with no education. Two cut-off points were assessed: <4 and <3. A cut-off of <4 showed better sensitivity versus <3, particularly for low-educated groups. A cut-off of <3 provided better specificity versus <4. Error analysis showed that errors made by low-educated participants without dementia were similar to those of patients with dementia. Conclusions: These findings show that the CDT (both total score and qualitative error analysis) has limited value in dementia case-finding in low-educated groups. The CDT is recommended primarily for middle- and high-educated groups.

Authors 5

1. Janique Boots-van der Heiden corresponding

   OLVG · Isala

   Affiliation as printed

   Department of Geriatrics, OLVG Hospital, 1061 AE Amsterdam, The Netherlands

   Department of Palliative Care, Isala Hospital, 8025 AB Zwolle, The Netherlands

2. Jos van Campen

   OLVG · Maasstad Ziekenhuis

   Affiliation as printed

   Department of Geriatrics, Maasstad Hospital, 3079 DZ Rotterdam, The Netherlands

   Department of Geriatrics, OLVG Hospital, 1061 AE Amsterdam, The Netherlands

3. Tessa Kooistra Aachen Department of Geriatrics, Alrijne Hospital

   Alrijne Ziekenhuis

   Affiliation as printed

   Department of Geriatrics, Alrijne Hospital, 2353 GA Leiderdorp, The Netherlands

4. Irene E. van de Vorst
   Affiliation as printed

   Independent Researcher, 1061 AE Amsterdam, The Netherlands

5. Miriam Goudsmit

   OLVG

   Affiliation as printed

   Department of Psychiatry & Medical Psychology, OLVG Hospital, 1061 AE Amsterdam, The Netherlands