Table 2.

Demographical and clinical information for prodromal PD (P-PD) and control group

Variable	Descriptive statistics						p
	Prodromal PD			Control			Prodromal PD
	n = 62			n = 62			vs. Control
	Mean	SD	n	Mean	SD	n
Sex, M/F	37/25		62	38/24		62	p = 1.000
Age, y	63.52	5.96	62	63.70	8.04	62	p = 0.793
RBDSQ (/13)	9.07	1.83	62	2.00	1.79	62	p < 0.001
Sniffin’Stick (/16)	10.11	3.19	53	14.18	1.06	62	p < 0.001
BSIT-A (/12)	6.48	1.94	61	NA	NA	0	NA
Education, y	13.00	4.25	60	13.76	3.66	62	p = 0.415
MDS-UPDRS I (/32)	8.22	5.96	46	4.65	4.49	62	p < 0.001**
MDS-UPDRS II (/32)	2.68	4.01	57	1.10	1.77	62	p = 0.004**
MDS-UPDRS III (/132)	4.71	6.57	59	4.19	5.06	59	p = 0.872
BDI-I (/63)	8.69	6.89	54	5.34	5.13	62	p = 0.004**
SAS (/42)	13.56	5.32	55	9.93	5.09	61	p < 0.001**
PDQ-39 (%)	13.32	12.63	53	5.87	6.15	61	p < 0.001**

Both groups were defined on RBDSQ, Sniffin’Stick and BSIT-A and matched for sex and age. SD, standard deviation; M, male; F, female; n, sample size; MDS-UPDRS, Movement Disorder Society –Unified Parkinson’s Disease Rating Scale; RBDSQ, REM Sleep Behavior Disorder (RBD) Screening Questionnaire; BSIT, Brief Smell Identification Test; BDI-I, Beck Depression Inventory; SAS, Starkstein Apathy Scale; PDQ-39, Parkinson’s disease questionnaire 39-item. ^*Significant at the unadjusted 5% level (p≤0.05) (two-tailed); ^**Significant at the Bonferroni-adjusted 5% level (p≤0.05/7) (two-tailed).