Browsing by Author "Kaasinen, Valtteri"

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    Cross-Cultural Differences in Patient Perceptions of Dyskinesia in Parkinson's Disease.
    (Mov Disord, 2023-01-20) Kaasinen, Valtteri; Luo, Sheng; Martinez-Martin, Pablo; Goetz, Christopher G; Stebbins, Glenn T
    BACKGROUND: The prevalence of levodopa-induced dyskinesia (LID) in Parkinson's disease (PD) varies among geographical regions. Cultural differences in patient-based perceptions of LID have not been studied. OBJECTIVE: We compared patient and clinician evaluations of LID severity across multiple cultures in patients with PD. METHODS: The data set included the Unified Dyskinesia Rating (UDysRS) scores from 16 language translation programs (3566 patients). We defined the Perception Severity Index (PSI) as the ratio between normalized patient-based subjective ratings (UDysRS Part 1B) and normalized clinician examination (Parts 3 and 4) scores (Part 1B/Parts 3 + 4) and compared the PSI across languages. RESULTS: The mean PSI for the Chinese language (2.16) was higher than those of all other languages, whereas the ratio for the Korean language (0.73) was lower than those for Japanese, German, Turkish, Greek, Polish, and Finnish languages (corrected P values <0.05). CONCLUSIONS: Culture, as represented by language, affects the subjective perception of LID and needs to be considered in multinational clinical PD trials on dyskinesia. © 2023 International Parkinson and Movement Disorder Society.
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    Validation of the Finnish Version of the Unified Dyskinesia Rating Scale.
    (European neurology, 2021-07-14) Kaasinen, Valtteri; Scheperjans, Filip; Kärppä, Mikko; Korpela, Jaana; Brück, Anna; Sipilä, Jussi OT; Joutsa, Juho; Järvelä, Juha; Eerola-Rautio, Johanna; Martikainen, Mika H; Airaksinen, Katja; Stebbins, Glenn T; Martinez-Martin, Pablo; Goetz, Christopher G; Lin, Jeffrey; Luo, Sheng; Pekkonen, Eero

    Introduction

    The Unified Dyskinesia Rating Scale (UDysRS) was developed to provide a comprehensive rating tool of dyskinesia in Parkinson's disease (PD). Because dyskinesia therapy trials involve multicenter studies, having a scale that is validated in multiple non-English languages is pivotal to international efforts to treat dyskinesia. The aim of the present study was to organize and perform an independent validation of the UDysRS Finnish version.

    Methods

    The UDysRS was translated into Finnish and then back-translated into English using 2 independent teams. Cognitive pretesting was conducted on the Finnish version and required modifications to the structure or wording of the translation. The final Finnish version was administered to 250 PD patients whose native language is Finnish. The data were analyzed to assess the confirmatory factor structure to the Spanish UDysRS (the reference standard). Secondary analyses included an exploratory factor analysis (EFA), independent of the reference standard.

    Results

    The comparative fit index (CFI), in comparison with the reference standard factor structure, was 0.963 for Finnish. In the EFA, where variability from sample to sample is expected, isolated item differences of factor structure were found between the Finnish and Reference Standard versions of the UDysRS. These subtle differences may relate to differences in sample composition or variations in disease status.

    Conclusion

    The overall factor structure of the Finnish version was consistent with that of the reference standard, and it can be designated as the official version of the UDysRS for Finnish speaking populations.