Table 2.

Characteristics of patients with Parkinson's disease (PD) with and without psychotic symptoms.

Variable	No. (%)		P
	PD with psychotic symptoms (n=63)	PD without psychotic symptoms (n=273)
Age at PD diagnosis (yr)*	66.24±9.83	66.13±10.77	0.982†
Gender
Men	41 (65.1)	158 (57.9)	0.294‡
Women	22 (34.9)	115 (42.1)
Ethnicity
Chinese	56 (88.9)	232 (85.0)	0.424‡
Malay/Indian/other	7 (11.1)	41 (15.0)
Years of education*	7.60±4.45	7.37±5.43	0.617†
Duration of follow-up at first onset of psychosis (yr)*	3.81±1.95
MMSE§
MMSE <25	22 (34.9)
MMSE ≥25	32 (50.8)
Missing	9 (14.3)
H&Y stage
Stage 1	1 (1.6)
Stage 2	28 (44.4)
Stage 3	7 (11.1)
Stage 4	10 (15.9)
Stage 5	5 (7.9)
MMSE score per calendar year*
2006	26.18±3.34	25.58±3.16	<0.001¶
2007	24.74±5.37	24.92±4.36
2008	24.51±4.09	24.84±4.29
2009	22.66±5.76	24.17±5.64
2010	23.83±6.01	25.18±3.32
2011	23.64±4.45	24.44±4.18
2012	24.93±4.92	24.83±4.77
2013	21.70±6.03	23.39±4.83
H&Y staging per calendar year*
2006	1.97±0.67	2.25±0.77	<0.001¶
2007	2.25±0.76	2.18±0.72
2008	2.27±0.79	2.09±0.73
2009	2.32±0.74	2.16±0.74
2010	2.44±0.87	2.20±0.76
2011	2.54±0.87	2.21±0.77
2012	2.69±1.02	2.35±0.91
2013	3.02±1.13	2.55±0.96

*Data presented as mean±standard deviation. ^†Mann-Whitney U test for continuous variables. ^‡Chi-square test for categorical variables. ^§MMSE score±12 months of onset of psychosis. ^¶Univariate regression analysis. H&Y: Modified Hoehn and Yahr Staging Scale, MMSE: Mini-Mental State Examination