Subject-investigator reproducibility of the Unified Parkinson's Disease Rating Scale.
OBJECTIVE
To evaluate the subject-investigator agreement on the Unified Parkinson's Disease Rating Scale (UPDRS) subsections I and II.


METHODS
Subject-investigator agreement was estimated at baseline and endpoint by Kappa statistics for individual items and concordance correlations for subscale totals using data from two NIH Exploratory Trials in Parkinson's Disease studies.


RESULTS
All but two questions had moderate subject-investigator agreement at baseline and endpoint. Participants consistently rated their disease activity worse that investigators.


CONCLUSIONS
UPDRS self-administration produces similar results to investigator-administration. Although slightly elevated, UPDRS self-administration can be accommodated in a clinical trial setting.
Division of Biostatistics & Epidemiology, Medical University of South Carolina, Charleston, SC 29425, USA.
Sydney E
SE
Seidel
Barbara C
BC
Tilley
Peng
P
Huang
Yuko Y
YY
Palesch
Kenneth J
KJ
Bergmann
Christopher G
CG
Goetz
Christopher J
CJ
Swearingen
D017322:Clinical Trials, Phase II as Topic; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis*; D010820:Physicians; D015203:Reproducibility of Results; D057566:Self Report; D012720:Severity of Illness Index