BACKGROUND AND OBJECTIVES: 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.
BACKGROUND AND OBJECTIVES: The 26-item Parkinson disease dyskinesia scale (PDYS-26) was developed to assess the impact of Parkinson's diseaselevodopa-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:PDpatients 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: Donald L Patrick; Laurie B Burke; Chad J Gwaltney; Nancy Kline Leidy; Mona L Martin; Elizabeth Molsen; Lena Ring Journal: Value Health Date: 2011-10-13 Impact factor: 5.725
Authors: Carlo Colosimo; Pablo Martínez-Martín; Giovanni Fabbrini; Robert A Hauser; Marcelo Merello; Janis Miyasaki; Werner Poewe; Cristina Sampaio; Olivier Rascol; Glenn T Stebbins; Anette Schrag; Christopher G Goetz Journal: Mov Disord Date: 2010-07-15 Impact factor: 10.338