Diagnostic utility of the Key Search Test as a measure of executive functions

Authors

  • Joukje M. OOSTERMAN,

    Corresponding author
    1. Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
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  • Meike MOLENVELD,

    1. Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
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  • Marcel G. M. OLDE RIKKERT,

    1. Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
    2. Department of Geriatric Medicine, Alzheimer Centre Nijmegen, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
    3. Department of Medical Psychology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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  • Roy P. C. KESSELS

    1. Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
    2. Department of Geriatric Medicine, Alzheimer Centre Nijmegen, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
    3. Department of Medical Psychology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Dr Joukje M. Oosterman PhD, Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3, 6500 HE Nijmegen, the Netherlands. Email: j.oosterman@donders.ru.nl

Abstract

Background:  Executive function deficits are commonly observed in many clinical populations, highlighting the importance of appropriate diagnostic tools to screen for these deficits. Most neuropsychological tests of executive function, however, are time-consuming and difficult to administer in the case of moderate to severe cognitive decline. The aim of the present study was to examine whether the Key Search Test, a short and easy to administer test, is a useful indicator of executive function deficits in a study sample with a diagnosis of cognitive impairment.

Methods:  Participants consisted of elderly people visiting the memory clinic at the department of geriatrics of a university medical center (n= 140) and of elderly controls (n= 37). Next to the Key Search Test, other executive function tests and a memory test were administered.

Results:  Low to moderate correlations were found between the Key Search Test and other executive function tests. Furthermore, although the Key Search Test discriminated significantly between intact and impaired executive function (AUC = 0.677, P < 0.001), sensitivity and specificity were low and no optimal cut-off point could be determined.

Conclusion:  The Key Search test might not be an appropriate measure of executive functions in cognitively impaired individuals.

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