title: Assessment of Parkinson's disease levodopa-induced dyskinesia: a qualitative research study.
abstract: OBJECTIVE
  The 26-item Parkinson disease dyskinesia scale (PDYS-26) was developed to assess the impact of Parkinson's disease levodopa-induced dyskinesias (PD-LID). The purpose of this qualitative research study was to assess the content validity of the PDYS-26 in an independent sample and to use the findings to suggest a conceptual framework around the impact of PD-LID.
  
  
  METHODS
  PD patients experiencing LID and their caregivers were recruited from four US clinical sites. Stage I involved 22 qualitative concept elicitation interviews with patients and caregivers, and 11 qualitative cognitive interviews (CI) with patients about the PDYS-26. The PDYS-26 was modified based on Stage I findings. Stage II consisted of 13 CI on the Modified PDYS.
  
  
  RESULTS
  Forty-six participants were interviewed across both stages of the study. Patient mean age was 67.3 (SD ± 9.55) years; 19 (54.3 %) female; 34 (97.1 %) white. The content validity of the PDYS-26 was generally supported. A revised conceptual framework with three hypothesized domains (body control, activities of daily living, social consequences) was developed. Modifications were made to the PDYS-26 (i.e., emphasizing LID in the instructions; response scale modification; deleting or modifying items), which resulted in the 22-item Modified PDYS.
  
  
  CONCLUSIONS
  Stage I and II findings suggested a number of modifications to the scale in order to improve the content validity. Psychometric testing of the revised scale with a larger patient sample is suggested to evaluate item performance, establish scoring, and provide quantitative support for the conceptual framework.
authors: Evidera, 430 Bedford Street, Suite 300, Lexington, MA, USA, william.lenderking@evidera.com.
authors: William R
authors: WR
authors: Lenderking
authors: Sally
authors: S
authors: Mannix
authors: Jennifer
authors: J
authors: Petrillo
authors: Christopher
authors: C
authors: Kenney
authors: Amanda
authors: A
authors: Landrian
authors: Anette-Eleonore
authors: AE
authors: Schrag
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017028:Caregivers; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy*; D011594:Psychometrics; D036301:Qualitative Research; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D007980:Levodopa
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