Is the Parkinson anxiety scale comparable across raters?

Maria João Forjaz, Alba Ayala, Pablo Martinez-Martin, Kathy Dujardin, Gregory M. Pontone, Sergio E. Starkstein, Daniel Weintraub, Albert F.G. Leentjens

Research output: Contribution to journalArticle

Abstract

The Parkinson Anxiety Scale is a new scale developed to measure anxiety severity in Parkinson's disease specifically. It consists of three dimensions: persistent anxiety, episodic anxiety, and avoidance behavior. This study aimed to assess the measurement properties of the scale while controlling for the rater (self- vs. clinician-rated) effect. The Parkinson Anxiety Scale was administered to a cross-sectional multicenter international sample of 362 Parkinson's disease patients. Both patients and clinicians rated the patient's anxiety independently. A many-facet Rasch model design was applied to estimate and remove the rater effect. The following measurement properties were assessed: fit to the Rasch model, unidimensionality, reliability, differential item functioning, item local independency, interrater reliability (self or clinician), and scale targeting. In addition, test-retest stability, construct validity, precision, and diagnostic properties of the Parkinson Anxiety Scale were also analyzed. A good fit to the Rasch model was obtained for Parkinson Anxiety Scale dimensions A and B, after the removal of one item and rescoring of the response scale for certain items, whereas dimension C showed marginal fit. Self versus clinician rating differences were of small magnitude, with patients reporting higher anxiety levels than clinicians. The linear measure for Parkinson Anxiety Scale dimensions A and B showed good convergent construct with other anxiety measures and good diagnostic properties. Parkinson Anxiety Scale modified dimensions A and B provide valid and reliable measures of anxiety in Parkinson's disease that are comparable across raters. Further studies are needed with dimension C.

Original languageEnglish (US)
Pages (from-to)545-551
Number of pages7
JournalMovement Disorders
Volume30
Issue number4
DOIs
StatePublished - Apr 1 2015

Keywords

  • Anxiety
  • Parkinson's disease
  • Rasch analysis
  • Rater

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology

Fingerprint Dive into the research topics of 'Is the Parkinson anxiety scale comparable across raters?'. Together they form a unique fingerprint.

  • Cite this

    Forjaz, M. J., Ayala, A., Martinez-Martin, P., Dujardin, K., Pontone, G. M., Starkstein, S. E., Weintraub, D., & Leentjens, A. F. G. (2015). Is the Parkinson anxiety scale comparable across raters? Movement Disorders, 30(4), 545-551. https://doi.org/10.1002/mds.26111