Correlation Between Quality of Life and Severity of Parkinson's Disease

This study aim to evaluate the correlation between Quality of Life (QoL) and severity of Parkinson's Disease (PD) by assessing the presence of an optimal cut-off point on the Parkinson's disease questionnaire (PDQ-39) as related to the Hoehn \& Yahr (H\&Y) scale in a cohort of Italian adults with PD. A multicenter, cross-sectional study was performed in central and northern Italy. This study was conducted on a cohort of consecutive individuals at three neurologic outpatient clinics. All participants were evaluated with the PDQ-39, and the severity of PD was recorded according to the H\&Y scale by a neurologist. Receiver operating characteristic (ROC) curves and coordinates of the curve, which were visually inspected, were used to find cut-off points with optimal sensitivity and specificity. These were in turn used to determine the optimal PDQ-39 cut-off score for identifying disease severity according to H\&Y stages.