Table 1.

Clinical characteristics of cases with Parkinson's disease non-demented (PDnD) and Parkinson's disease dementia (PDD).

	PDnD	PDD	p
	N = 71	N = 81
Sex, male (%)	43 (60.6)	57 (70.4)	0.271
Age at disease onset, mean (SD)	61.3 (13.0)	64.2 (9.5)	0.117
Age at dementia onset, mean (SD)	-	73.7 (7.0)	-
Disease duration, mean (SD)	15.5 (7.7)	13.6 (6.7)	0.102
Motor dementia interval, mean (SD)	-	9.4 (5.8)	-
Dementia duration, mean (SD)	-	4.1 (2.8)	-
Age at death, mean (SD)	77.0 (9.3)	77.8 (6.5)	0.515

SD: standard deviation. P value from t-tests for continuous variables and chi-square tests for categorical variables (sex).