Expanded and independent validation of the Movement Disorder Society–Unified Parkinson’s Disease Rating Scale (MDS-UPDRS)

Abstract

The Movement Disorder Society-UPDRS (MDS-UPDRS) was published in 2008, showing satisfactory clinimetric results and has been proposed as the official benchmark scale for Parkinson's disease. The present study, based on the official MDS-UPDRS Spanish version, performed the first independent testing of the scale and adds information on its clinimetric properties. The cross-culturally adapted MDS-UPDRS Spanish version showed a comparative fit index ≥ 0.90 for each part (I-IV) relative to the English-language version and was accepted as the Official MDS-UPDRS Spanish version. Data from this scale, applied with other assessments to Spanish-speaking Parkinson's disease patients in five countries, were analyzed for an independent and complementary clinimetric evaluation. In total, 435 patients were included. Missing data were negligible and moderate floor effect (30 %) was found for Part IV. Cronbach's α index ranged between 0.79 and 0.93 and only five items did not reach the 0.30 threshold value of item-total correlation. Test-retest reliability was adequate with only two sub-scores of the item 3.17, Rest tremor amplitude, reaching κ values lower than 0.60. The intraclass correlation coefficient was higher than 0.85 for the total score of each part. Correlation of the MDS-UPDRS parts with other measures for related constructs was high (≥ 0.60) and the standard error of measurement lower than one-third baseline standard deviation for all subscales. Results confirm those of the original study and add information on scale reliability, construct validity, and precision. The MDS-UPDRS Spanish version shows satisfactory clinimetric characteristics.

Tablet-Based Application for Objective Measurement of Motor Fluctuations in Parkinson Disease

“…As subjective scales are limited in accuracy and reliability [1], a moderate correlation suggests a tablet-based application may be capable of detecting differences in motor function beyond those probed by the MDS-UPDRS-III. In fact, the test-retest reliability for both medication states was higher than that reported for the MDS-UPDRS-III (0.60–0.71) [26]. Thus, a “perfect” correlation of any technology-based objective measure with MDS-UPDRS-III scores may not be achievable or even desirable if objective measures capture motor data more accurately and reliably.…”

Relationship between the non-motor items of the MDS–UPDRS and Quality of Life in patients with Parkinson's disease

“…The main aim of this revision was to address the shortages of the original scale, to improve scale properties and cover a bigger number of PD manifestations particularly including some non-motor symptoms (NMS), which were not part of the original scale. The MDS-UPDRS has demonstrated good reliability and validity also in multiple other studies [3][4][5].…”

Age, Gender, Comorbidity, and the MDS-UPDRS: Results from a Population-Based Study

“…The MDS-UPDRS has been extensively validated in individuals with PD in clinical settings [5,6] , but its performance in those without PD in the general population has not been systematically assessed. Thus, the effect of 'normal aging' and comorbid medical conditions on an individual's score is unknown.…”