ABSTRACT
The Pentagon Drawing Test (PDT) is a common cognitive screening test.
Objective:
The aim of this study was to evaluate performance properties of a specific PDT scoring scale in older adults with Alzheimer's disease (AD) and healthy controls.
Methods:
A cross-sectional study of 390 elderly patients, aged 60 years or older with at least two years of education was conducted. All participants completed clinical and neuropsychological evaluations, including the Cambridge Cognitive Examination, the Mini-Mental State Examination (MMSE), and the Clock Drawing Test. All PDT were blindly scored with the scale of Bourke et al.
Results:
PDT analyses of the binary score on the MMSE (0 or 1 point) did not discriminate AD from controls (p = 0.839). However, when PDT was analyzed using the Bourke et al. scale, the two groups could be distinguished (p <0.001). PDT was not affected by education, showed sensitivity of 85.5% and specificity of 66.9%, discriminated different clinical stages of dementia, and correlated with the other cognitive tests (p <0.001). A 1-point difference on the Bourke et al. scale was associated with an odds ratio of 3.46 for AD.
Conclusion:
PDT can be used as a cognitive screen for suspected cases of dementia, especially AD, irrespective of educational level.
Key words:
Alzheimer's disease; cognitive assessment; screening instrument
