Rating Scales & Outcome Measures

Hoehn and Yahr (HY), UPRDS, PRO-PD, etc.
What do these tell rating scales tell us?
Why do we use scales in research that aren't considered relevant in clinic?
Is there a difference between measuring wellness and measuring disease?
This is a clip taken from Parkinson's School course from the Library entitled, "How Do We Know What We Know?"
www.Parkinson-School.com

[@Sociable_Graces]

Heartfelt gratitude for your abundant dedication!