The Clinically Important Difference on the Unified Parkinson's Disease Rating Scale

Objective: To determine the estimates of minimal, moderate, and large clinically important differences (CIDs) for the Unified Parkinson's Disease Rating Scale (UPDRS).Design: Cross-sectional analysis of the CIDs for UPDRS total and motor scores was performed on patients with Parkinson disease (PD) using distribution-and anchorbased approaches based on the following 3 external standards: disability (10% on the Schwab and England Activities of Daily Living Scale), disease stage (1 stage on the Hoehn and Yahr Scale), and quality of life (1 SD on the 12-Item Short Form Health Survey).