Extensive validation study of the Parkinson's Disease Composite Scale

Martinez-Martin, Pablo and Radicati, Fabiana Giada and Rodriguez Blazquez, Carmen and Wetmore, John and Kovács, Norbert (2019) Extensive validation study of the Parkinson's Disease Composite Scale. EUROPEAN JOURNAL OF NEUROLOGY, 26 (10). pp. 1281-1288. ISSN 1351-5101

Text 2019_EurJNeurolPDCS19261281.pdf Restricted to Registered users only Download (200kB) | Request a copy

Abstract

A composite instrument able to rapidly and reliably assess the most relevant motor and non-motor afflictions suffered by Parkinson's disease (PD) patients in a real world clinic setting is an unmet need. The recently-validated PD Composite Scale (PDCS) was designed to fulfill this gap as a quick, comprehensive PD assessment.Extensive evaluation of the PDCS's clinimetric properties using a large international sample.Cross-sectional study in which the PDCS, the Movement Disorder Society-Unified Parkinson's Disease Rating Scale, and the Clinical Impression of Severity Index for PD were applied. Basic clinimetric attributes of the PDCS were analyzed.776 PD patients were included. The PDCS total score showed negligible floor and ceiling effect. Three factors (54.5% of the variance) were identified: Factor 1 which included motor impairment, fluctuations, and disability; Factor 2, non-motor symptoms; and Factor 3, tremor and complications of therapy. Cronbach's alpha was from 0.66 to 0.79. Inter-rater reliability showed weighted kappa values from 0.79 to 0.98 for items and intraclass correlation coefficient values from 0.95 (Disability) to 0.99 (Motor and Total score). The Bland-Altmann method, however, showed irregular concordance. PDCS standard error of measurement and convergent validity with equivalent constructs of other measures were satisfactory (≥0.70). PDCS scores significantly differed by Hoehn and Yahr stage.Overall, in line with previous findings, the PDCS is a feasible, acceptable, valid, reliable, and precise instrument for quickly and comprehensively assessing PD patients. This article is protected by copyright. All rights reserved.

Actions (login required)

Edit Item