Health-related quality-of-life scales in Parkinson's disease: critique and recommendations.

Health-related quality of life is an important patient-reported outcome used in intervention trials and for monitoring the consequences of health status on physical, mental, and social domains. Parkinson's disease is a complex disorder that strongly affects patients' quality of life. Several health-related quality of life tools have been used in Parkinson's disease. A Movement Disorder Society Task Force was commissioned to rate the psychometric quality of available health-related quality of life scales as applied to Parkinson's disease. Following the methodology adopted by previous work of the Movement Disorder Society Task Force, a review of generic and specific health-related quality of life scales applied in studies on Parkinson's disease was completed. Considering the scales from 3 perspectives-use in Parkinson's disease, use by multiple research groups, and clinimetric properties-a final classification as "recommended," "suggested," or "listed" was applied to each reviewed instrument. Four generic scales (EuroQoL, Nottingham Health Profile, 36-Item Short-Form Health Survey, and Sickness Impact Profile) and 5 specific scales (39-Item Parkinson's Disease Questionnaire, Parkinson's Disease Questionnaire Short Form, Parkinson's Disease Quality of Life Questionnaire, Parkinson's Impact Scale, and Scales for Outcomes in Parkinson's Disease-Psychosocial) reached the level of "recommended." The 39-item Parkinson's Disease Questionnaire is the most thoroughly tested and applied questionnaire. Three other generic measures (Quality of Life Questionnaire 15D, Schedule for the Evaluation of Individual Quality of Life-Direct Weighting, and World Health Organization Quality of Life Assessment Short Version) and the specific Parkinson's Disease Quality of Life Scale are "suggested." With a little additional effort in completing the stipulated requirements, they could reach the "recommended" level. At present there is a wide variety of health-related quality of life measures for application in the Parkinson's disease setting, and the task force does not recommend the development of a new scale. Selection of the most appropriate instrument for a particular objective requires consideration of the characteristics of each scale and the goals of the assessment.