Validation of Slovak version of the Movement Disorder Society – Unified Parkinson’s Disease Rating Scale (MDS-UPDRS)

Recommendations for revision of the original version of Unified Parkinson’s Disease Rating Scale (UPDRS) were published based on its critique. Subsequently, a Movement Disorders Society (MDS)sponsored revision designated as the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) was presented. After its successful clinimetric testing, a program for translation and validation of non-English versions of the MDS-UPDRS was initiated. The aim of this study was to validate and confirm the factor structure of the Slovak translation of the MDS-UPDRS. We examined 354 patients with Parkinson’s disease in all Hoehn and Yahr stages with the Slovak version of MDS-UPDRS. The average age of our sample was 68 ± 9.5 years and average disease duration was 6.7 ± 5.1 years. Slovak data were compared using confirmatory factor analysis with the original English data. A pre-specified criterion for approving the Slovak translation as an official version of the MDS-UPDRS was a comparative fit index (CFI) ≥ 0.90 for all four parts of the Slovak MDS-UPDRS. Exploratory factor analysis was performed to explore the underlying factor structure without the constraint of a pre-specified factor structure. For all four parts of the Slovak MDS-UPDRS, the CFI, in comparison with the English-language factor structure, was 0.91 or greater. Isolated differences in the factor structure of the Slovak MDS-UPDRS were identified by exploratory factor analysis compared with the English version.