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

Following its critique, recommendations for revision of the original version of the Unified Parkinson's Disease Rating Scale (UPDRS) were published. Subsequently, the Movement Disorder Society (MDS) - sponsored revision entitled Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) was presented. After its successful clinimetric testing, a programme 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 the MDS-UPDRS. The mean age of our sample was 68 +/- 9.5 years and the mean disease duration was 6.7 +/- 5.1 years. Slovak data were compared using confirmatory factor analysis with the original English language data. The pre-specified criterion for approving the Slovak translation as an official version of the MDS-UPDRS was the comparative fit index (CFI) >= 0.90 for all four parts of the Slovak MDS-UPDRS. An exploratory factor analysis was performed to explore the underlying factor structure without the constraints of a pre-specified factor structure. When compared to the English-language factor structure, the CFI for all four parts of the Slovak MDS-UPDRS was 0.91 or greater. Isolated differences in factor structure of the Slovak MDS-UPDRS compared to the English version were identified by exploratory factor analysis. The Slovak version of the MDS-UPDRS was accredited as the sixth official non-English translation of the MDS-UPDRS and can be downloaded from the Movement Disorder Society's website (http://www.movementdisorders.org/publications/rating_scales/), along with training materials using the Slovak translation. In this paper, we also present the major changes and advantages of the Slovak MDS-UPDRS compared with the original UPDRS.