Browsing by Subject "Clinimetrics"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Successful use of the Unified Dyskinesia Rating Scale regardless of PD- or dyskinesia-duration.
    (Parkinsonism & related disorders, 2019-10) Ren, Xuehan; Lin, Jeffrey; Luo, Sheng; Goetz, Christopher G; Stebbins, Glenn T; Cubo, Esther
    OBJECTIVE:We assessed differential item functioning (DIF) in the Unified Dyskinesia Rating Scale (UDysRS) to evaluate bias risk from the duration of Parkinson's Disease (PD) and duration of dyskinesia. BACKGROUND:Assessing DIF is a core validation step for rating scales. If DIF is present for an item, interpretation must consider influences from the tested covariates. DIF can be uniform or non-uniform, depending on the consistency of influence from the given covariate across all levels of dyskinesia. METHODS:Using a large UDysRS database (N = 2313), uniform and non-uniform DIF related to the duration of PD and/duration of dyskinesia were tested. Unidimensionality of UDysRS was first confirmed using confirmatory factor analysis. DIF analysis was conducted using two independent latent models. DIF in an item was confirmed if both methods independently identified DIF at a significance level using Bonferroni correction. McFadden pseudo R^2 measured clinical relevancy of DIF magnitude (negligible, moderate, and large) for items identified with DIF, and items with DIF were considered clinically relevant if they exceeded a negligible designation. RESULTS:Most items did not show uniform or non-uniform DIF based on PD and dyskinesia duration in isolation or in combination. For all items where DIF was identified, the magnitude statistic was in the negligible range (McFadden pseudo R^2 < 0.035) and the combined impact of multiple identified DIF items on UDysRS likewise did not exceed the negligible designation. CONCLUSION:The absence of clinically relevant DIF suggests that the UDysRS can be applied across all patients regardless of their PD- or dyskinesia-duration.
  • Thumbnail Image
    ItemOpen Access
    Validation of the Hebrew Version of the Unified Dyskinesia Rating Scale.
    (Neuroepidemiology, 2020-06-15) Faust-Socher, Achinoam; Anis, Saar; Kestenbaum, Meir; Shabtai, Herzl; Taichman, Tali; Bar David, Aya; Ezra, Adi; Peretz, Chava; Rosenberg, Alina; Brozgol, Marina; Herman, Talia; Stebbins, Glenn T; Goetz, Christopher G; Martínez-Martín, Pablo; Luo, Sheng T; Ren, Xuehan; Giladi, Nir; Gurevich, Tanya
    BACKGROUND:The Unified Dyskinesia Rating Scale (UDysRS) is a well-established tool for producing comprehensive assessments of severity and disability associated with dyskinesia in patients with Parkinson's disease (PD). The scale was originally developed in English, and a broad international effort has been undertaken to develop and validate versions in additional languages. Our aim was to validate the Hebrew version of the UDysRS. METHODS:We translated the UDysRS into Hebrew, back-translated it into English, and carried out cognitive pretesting. We then administered the scale to non-demented native Hebrew-speaking patients who fulfilled the Brain Bank diagnostic criteria for probable PD (n = 250). Data were compared to the Reference Standard data used for validating UDysRS translations. RESULTS:The different portions of the Hebrew UDysRS showed high internal consistency (α ≥ 0.92). A confirmatory factor analysis in which we compared the Hebrew UDysRS to the Reference Standard version produced a comparative fit index (CFI) of 0.98, exceeding the threshold criterion of CFI > 0.9 indicating factor validity. A secondary exploratory factor analysis provided further support to the consistency between the factor structures of the Hebrew and Reference Standard versions of the UDysRS. CONCLUSION:The UDysRS Hebrew version shows strong clinimetric properties and fulfills the criteria for designation as an official International Parkinson and Movement Disorder Society-approved translation for use in clinical and research settings.