Validation of the Norwegian version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale

Authors

• Guido Alves
• Yvonne Stavland Sørenes
• Veslemøy Hamre Frantzen
• Michaela Dreetz Gjerstad
• Anders Ledaal Bjørnestad
• Jodi Maple-Grødem
• Elin Bjelland Forsaa
• Ylva Hivand Hiorth
• Karen Herlofson
• Espen Benjaminsen
• Kari Anne Bjørnarå
• Espen Dietrichs
• Roberta Balestrino
• Carmen Gasca-Salas
• Chi-Ying R Lin
• Alvaro Sanchez-Ferro
• Michelle H S Tosin
• Tiago A Mestre
• Monica M Kurtis
• Pablo Martinez-Martin
• Sheng Luo
• Luowen Yu
• Glenn T Stebbins
• Christopher G Goetz
• MDS COA Translation Steering Committee

Language

English

Publication Date

1-1-2026

Journal

Clinical Parkinsonism & Related Disorders

DOI

10.1016/j.prdoa.2025.100420

PMID

41561570

PMCID

PMC12814832

PubMedCentral® Posted Date

1-6-2026

PubMedCentral® Full Text Version

Post-print

Abstract

Introduction: The Movement Disorder Society-revised version of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is the gold standard assessment for evaluating Parkinson's disease (PD) symptoms and severity, but a validated Norwegian version is not yet available. We translated the original English MDS-UPDRS into Norwegian and tested the clinimetrics of the translated version following the MDS-established protocol for non-English language translations.

Methods: Two independent teams translated the English version of the MDS-UPDRS into Norwegian. After review of the back-translated English version, cognitive pretesting was performed in twelve PD patients at one study site. This was followed by large-scale testing completed by 351 native Norwegian-speaking PD patients at six centers across Norway. We applied confirmatory and exploratory factor analyses to determine the validity of the Norwegian version. Additional analyses were performed to test the reliability of the translated scale.

Results: Confirmatory factor analysis demonstrated that the factor structure of the Norwegian version was consistent with that of the English version, as indicated by comparative fit indexes of ≥0.90 for all four MDS-UPDRS parts. Exploratory factor analysis showed the same number of factors in each MDS-UPDRS part, compared to the English version, with some differences in item loadings. Cronbach's α values were >0.70 for all four MDS-UPDRS parts.

Conclusion: The Norwegian language MDS-UPDRS has good construct validity and internal consistency, meeting the requirements to be designated as the Official Norwegian Version of the MDS-UPDRS. We recommend using this validated version in both research and clinical practice.

Keywords

Parkinson’s disease, MDS-UPDRS, Validation, Validity, Reliability

Published Open-Access

yes

Recommended Citation

Alves, Guido; Sørenes, Yvonne Stavland; Frantzen, Veslemøy Hamre; et al., "Validation of the Norwegian version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale" (2026). Faculty, Staff and Students Publications. 7224.
https://digitalcommons.library.tmc.edu/baylor_docs/7224