Disability Rating Scales in Parkinson's Disease: Critique and Recommendations

Introduction: PD is associated with impairments that progress over time to disability. A large number of disability scales exist with little information on the best choice in PD. Methods: Following methodology adopted by the International Parkinson and Movement Disorder Society Task Force, a review of disability scales used in PD was completed. Based on prespecified criteria, the review categorized scales into: “Recommended”; “Recommended with Further Validation in PD Required” when well-validated scales have not been specifically tested for clinimetric properties in PD; “Suggested”; and “Listed.”. Results: Twenty-nine disability instruments were identified with nine scales fulfilling criteria for “Recommended” and 7 “Recommended with Further Validation in PD Required.” Eight scales are “Suggested” and five scales are “Listed” for use in PD. The nine Recommended scales (Functional Status Questionnaire, Lawton-Brody Activities of Daily Living, Nottingham Activities of Daily Living, Schwab and England Activities of Daily Living, Self-Assessment PD Disability, Short Parkinson's Evaluation Scale/Scales for Outcomes in PD, Unified PD Rating Scale–II: Activities of Daily Living, Movement Disorders Society UPDRS Motor Experiences of Daily Living, PROMIS^® and Neuro-QoL Physical Function), and the seven Recommended with Further Validation in PD Required are reviewed. Conclusion: Many disability measures are available and recommended for application in PD. 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.