Purpose: Anxiety is a prevalent symptom of Parkinson's disease, but is often under-recognised and challenging to characterise. The present study aimed to develop a comprehensive new scale that characterised the specific and nuanced experience of anxiety in people living with Parkinson's disease. A shortened version of the scale was also developed. The psychometric properties of both versions of the scale were assessed for reliability and validity.
Methods: Secondary analyses were conducted on data from 254 people with Parkinson's disease and anxiety collected in a modified Nominal Group Technique ranking survey. Secondary analyses included exploratory factor analysis, reliability and validity analyses, and confirmatory factor analysis.
Results: A standardised scale of anxiety and Parkinson's disease, in its long Comprehensive Anxiety and Parkinson's Scale - 54 (CAPS-54) and short versions (CAPS-24), was developed. Reliability and validity analyses of the scales demonstrated excellent factorial and internal consistency, as well as good convergent validity.
Conclusions: The CAP Scales offer researchers and clinicians a more comprehensive means of assessing the experience of anxiety in the context of Parkinson's disease than is currently available. Initial validation of the scales is promising. Future validation and identification of clinical boundaries with an independent sample is recommended.
Keywords: Parkinson’s disease; anxiety; measure development; measurement scale; patient and public involvement.
Anxiety is a prevalent but under-recognised symptom of Parkinson’s disease; current assessment measures focus on common anxiety presentations.The Comprehensive Anxiety and Parkinson’s Scales (CAP-54 and CAP-24) offer a more comprehensive means of assessing the experience of anxiety in the context of Parkinson’s disease than is currently available.Using the CAP Scales may allow therapists to better tailor their interventions to the specific form of anxiety that their patients with Parkinson’s may experience.