Extensive validation study of the Parkinson's Disease Composite Scale

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

Examples of clinical application cases with temporal patterns of dyskinesia, tremor, and bradykinesia detected by the tool.

(a-b) Temporal patterns related to clinical application cases concerning the wearing-off phenomenon. (c) Temporal patterns related to clinical application cases concerning the early-morning OFF period.</p

A comparison between the data contained in the patient diaries and data provided in the PD-Watch report for each 24-h acquisition period.

The overall recording duration of 528 hours with twelve PD patients is divided in no. 22 acquisition periods, with a 24-h duration for each acquisition period. The symbol “#” is used to identify each 24-h acquisition period.</p

Data obtained through the PD-Watch tool for a 72-h acquisition of a PD patient with motor fluctuations.

(a) Pie chart on the percentage duration of the recorded motor states. (b) Daily histograms with motor state duration. (c) Color legend. (d) Temporal patterns provided by the PD-Watch for a 24-h sequence of the whole 72-h acquisition. First row: temporal patterns of motor states; second row: temporal pattern of dyskinesia intensity; third row: the temporal pattern of tremor intensity; fourth row: a spectrogram of the 24-h recording.</p

Supporting information reports more details on the study protocol, the inclusion criteria and the performances of the proposed tool.

The Supplementary figures show some examples of data obtained through the PD-Watch tool, including an application example related to the patient adherence to the oral therapy plan. (DOCX)</p

Outcome of the comparison between the data contained in the patient diaries and data provided in the PD-Watch report for each 24-h acquisition period.

The overall recording duration of 528 hours with twelve PD patients is divided in no. 22 acquisition periods, with a 24-h duration for each acquisition period. The symbol “#” is used to identify each 24-h acquisition period.</p

Fig 2 -

(a-d) Information on dyskinesia detected during 24-hour acquisitions for four different patients, from (a) to (d). First column: 24-h temporal pattern of dyskinesia intensity; second column: histogram of the time spent with impactful dyskinesia distributed for the different score values from 1 to 4; third column: the value of the MDS-UPDRS score for the items 4.1. and 4.2. (e-f) shows a comparison between the information on dyskinesia maximum intensity and duration detected by the tool and the MDS-UPDRS score for the items related to dyskinesia. (e) The relationship between the scores of item 4.2 of the MDS-UPDRS on the functional impact of the dyskinesias (comparable to the item 5 –wrist–of the AIMS) and the maximum intensity of the dyskinesia. (f) The relationship between the scores of item 4.1 of the MDS-UPDRS on the time/percent of the waking day spent with dyskinesia and the duration of impactful dyskinesia.</p

Applications of the European Parkinson’s Disease Association sponsored Parkinson’s Disease Composite Scale (PDCS)

This study was addressed to determine the presence of Parkinson disease (PD) manifestations, their distribution according to motor subtypes, and the relationships with health-related quality of life (QoL) using the recently validated European Parkinson's Disease Association sponsored Parkinson's Disease Composite Scale (PDCS). Frequency of symptoms was determined by the scores of items (present if >0). Using ROC analysis and Youden method, MDS-UPDRS motor subtypes were projected on the PDCS to achieve a comparable classification based on the PDCS scores. The same method was used to estimate severity levels from other measures in the study. The association between the PDCS and QoL (PDQ-39) was analyzed by correlation and multiple linear regression. The sample consisted of 776 PD patients. We found that the frequency of PD manifestations with PDCS and MDS-UPDRS were overlapping, the average difference between scales being 5.5% only. Using the MDS-UPDRS subtyping, 215 patients (27.7%) were assigned as Tremor Dominant (TD), 60 (7.7%) Indeterminate, and 501 (64.6%) Postural Instability and Gait Difficulty (PIGD) in this cohort. With this classification as criterion, the analogous PDCS-based ratio provided these cut-off values: TD subtype, >= 1.06 ; Indeterminate, 0.65 ; and PIGD, <0.65. The agreement between the two scales on this classification was substantial (87.6% ; kappa = 0.69). PDCS total score cut-offs for PD severity were: 23/24 for mild/moderate and 41/42 for moderate/severe. Moderate to high correlations (r = 0.35-0.80) between PDCS and PDQ-39 were obtained, and the four PDCS domains showed a significant independent influence on QoL. The conclusions are: (1) the PDCS assessed the frequency of PD symptoms analogous to the MDS-UPDRS ; (2) motor subtypes and severity levels can be determined with the PDCS ; (3) a significant association between PDCS and QoL scores exists