Use of a self-rating scale of the nature and severity of symptoms in Parkinson’s Disease (PRO-PD): Correlation with quality of life and existing scales of disease severity

Abstract

A self-rating scale was developed to permit patient-reported, remote assessment of Parkinson’s disease symptom severity. The goal was to create a continuous outcome measure that does not require a clinical exam, does not fluctuate in response to dopaminergic medications, takes only a few minutes to complete, allows for stratification by symptom(s), and captures both motor and nonmotor Parkinson’s disease symptoms, major contributors to quality of life. The Patient Reported Outcomes in Parkinson’s Disease (PRO-PD) is the cumulative score of 32 slider bars, each evaluating a common Parkinson’s disease symptom. The PRO-PD has been used as an outcome measure in three studies. The baseline data from each of these studies were pooled for this analysis. Symptom frequency and severity are described, as well as correlation coefficients with existing measures of Parkinson's disease severity. Data on 1031 participants with Parkinson's disease were available for analysis. Fatigue, impaired handwriting, daytime sleepiness, slowness, tremor, muscle cramps, and forgetfulness were the most frequently reported symptoms. Persons with a relatively long duration of Parkinson's disease tended to report more, and more severe, symptoms. The PRO-PD was most highly correlated with the Parkinson’s Disease Questionaire-39 (r = 0.763, P < 0.000) and Patient-Reported Outcome Measurement Information System Global quality of life (r = −0.7293, P < 0.000), other patient-reported quality of life measures. The PRO-PDnon-motor subset was highly correlated with the Non-Motor Symptom Score (r = 0.7533, P < 0.000). There was a moderate correlation seen with Hoehn & Yahr (r = 0.5922, P < 0.000), total Unified Parkinson’s disease Rating Scale (r = 0.4724, P < 0.000), and the Timed-Up-&-Go (r = 0.4709, P < 0.000). The PRO-PD may have utility for patients, providers, and researchers as a patient-centered measure of Parkinson’s disease symptom severity. Further PRO-PD validation efforts are warranted.