Comparison of demographic and clinical characteristics between PD patients and HC.

Demographic and clinical information of PPMI participants. Abbreviations: CI = 95% confidence interval; GDS = Geriatric Depression Scale; HC = healthy controls; MoCA = Montreal Cognitive Assessment; MDS-UPDRS = Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale; PD = Parkinson’s disease; SCOPA = Scale for Outcomes in Parkinson’s disease for Autonomic Symptoms SD = standard deviation; y = years. UPSIT = University of Pennsylvania Smell Identification Test.a Based on a Student t-test.b Based on chi-square test (X2).Comparison of demographic and clinical characteristics between PD patients and HC.