Development and Diagnostic Accuracy of a Shortened Dutch Naming Test for People with Aphasia Using Item Response Theory

Authors Eline Alons , Lotti Dijkhuis , Piet van Tuijl , Lizet van Ewijk
Published in Archives of Clinical Neuropsychology
Publication date 2022
Research groups Speech and Language Therapy: Participation through communication
Type Article

Summary

Objective The first objective was to assess the psychometric properties of the 92-item Dutch Naming Test (DNT-92), developed to assess word finding difficulties in people with aphasia, using Item Response Theory (IRT). The second objective was to select suitable items for a short version with a discriminative purpose. Method This study has a retrospective, psychometric research design, in which 510 DNT-92-forms of people with aphasia and 192 DNT-forms of healthy participants were used for analyses. An IRT analysis was performed and information on the item- and person parameters was obtained. Item selection for the short version was based on a combination of the discriminative ability of the items and their estimated theta or difficulty. Items with the highest information load, and a difficulty parameter in the range of overlap between the sample of people with aphasia and healthy participants were selected. Results A 2-PL IRT analysis showed best fit to the data. Assumptions of unidimensionality, local independence, and monotonicity were met. Items were removed incrementally, whilst checking sensitivity and specificity of the remaining short form. A selection of six items proved optimal in terms of sensitivity and specificity, with an area under the curve value of 0.85. Differences were found between participants younger than 70 and older. Conclusions The IRT assumptions for the DNT-92 were met, indicating that the test has good psychometric properties. A reduction of items to just six items proved possible, leading to a reliable six item short form with a discriminatory purpose.

On this publication contributed

  • Eline Alons
    Eline Alons
    • PhD candidate
    • Research groups: Speech and Language Therapy: Participation through communication
  • Lizet van Ewijk | Researcher | Research group Speech and Language Therapy: Participation through communication
    Lizet van Ewijk
    • Researcher
    • Research groups: Speech and Language Therapy: Participation through communication

Language English
Published in Archives of Clinical Neuropsychology
Year and volume 37 8
Key words aphasia, anomia, item response theory, differential item functioning, language tests
Page range 1735-1748

Eline Alons

Eline Alons

Eline Alons

  • PhD candidate
  • Research group: Speech and Language Therapy: Participation through communication