Table 4.

Sample characteristics by diagnostic group

Variable		Unimpaired	Impaired	p	d
Gender (female), %		65	43	0.02	N/A
n		65	60
Age	Mean ± SD	69.2 ± 6.9	71.9 ± 7.7
	Median	69.0	73	0.04	−0.37
	Range	50–84	52–85
	n	65	60
Ham-D	Mean ± SD	1.7 ± 2.1	2.8 ± 3.4	0.05	−0.41
	Median	1.0	2.0
	Range	0–7	0–17
	n	65	54
GDS	Mean±SD	2.9 ± 3.0	7.6 ± 5.3	<0.001	−1.16
	Median	2.0	7.5
	Range	0–13	0–21
	n	65	54
FAQ	Mean±SD	0.03 ± 0.17	11.4 ± 9.3	<0.001	−2.67
	Median	0	10
	Range	0–1	0–30
	n	65	53
NPI	Mean±SD	1.03 ± 1.9	4.4 ± 5.0	<0.001	−1.03
Severity	Median	0	3.0
	Range	0–8	0–20
	n	63	51
UPDRS	Mean±SD	0.14 ± 0.8	3.9 ± 7.9	0.001	−0.92
	Median	0	0
	Range	0–5	0–31
	n	65	56
MMSE	Mean±SD	29.6 ± 0.63	23.3 ± 7.1	<0.001	1.68
	Median	30	26.5
	Range	27–30	2–30
	n	64	60
DRS-2	Mean±SD	139.9 ± 3.3	113.8 ± 26.1	<0.001	1.85
	Median	141	124
	Range	127–144	23–140
	n	65	59
CDR, %	0	97	5	<0.001	N/A
	0.5	3	59
	1.0	0	22
	2.0	0	7
	3.0	0	7
	n	65	59

Statistical comparisons include χ² analyses for categorical data (gender, CDR), t test with equal variance assumed (age), and t test with equal variances not assumed (Ham-D, GDS, FAQ, NPI Severity, UPDRS, MMSE, DRS). d = Cohen's d effect size; Ham-D = Hamilton Depression Scale; GDS = Geriatric Depression Scale; FAS = Functional Assessment Scale; NPI = Neuropsychiatric Inventory; UPDRS = Unified Parkinson's Disease Rating Scale; MMSE = Mini Mental State Exam; DRS-2 = Dementia Rating Scale-2nd Edition; CDR = Clinical Dementia Rating scale.