Table 1.

Demographics, hippocampal volumes, and memory tests scores for the study participants. Variables are reported either as N(%) for categorical variables or mean(sd) for continuous variables, and as adjusted mean(sd) from ANCOVA for LMT scores in each cognitive status.

Characteristic	Total (N=355)	CU (N=282)	MCI-AD (N=39)	Dementia-AD (N=34)	p Value	Post-hoc (p < .05)
Sex (female)	225 (71.8%)	200 (70.9%)	12 (30.8%)	13 (38.2%)	<.001
Sample (WRAP)	230 (64.8%)	224 (79.4%)	6 (15.4%)	0 (0%)	<.001
Age at MRI scan (years)	65.0 (9.4)	62.6 (7.8)	74.8 (7.0)	73.7 (11.7)	<.001	CU<MCI CU<Dem
Education (years)	16.1 (2.8)	16.3 (2.7)	16.2 (3.1)	14.5 (2.9)	.002	Dem<CU Dem<MCI
Elapsed time (months)	4.9 (3.7)	5.6 (3.7)	3.0 (2.9)	1.5 (1.1)	<.001	Dem<CU MCI<CU
APOE risk score	1.3 (0.8)	1.3 (0.8)	1.4 (0.8)	1.8 (1.0)	.001	CU<Dem
TIV (mL)	1471.9 (141.5)	1460.4 (139.3)	1542.9 (148.9)	1485.7 (129.3)	.002	CU<MCI
Left HV (mL)	3638.8 (528.2)	3770.7 (452.5)	3168.1 (479.8)	3084.1 (506.6)	<.001	MCI<CU Dem<CU
Right HV (mL)	3844.5 (542.0)	3955.4 (477.5)	3497.9 (522.3)	3322.1 (606.0)	<.001	MCI<CU Dem<CU
Recency ratio	1.1 (0.5)	1.0 (0.0)	1.4 (0.1)	2.0 (0.1)	<.001	CU<MCI CU<Dem MCI<Dem
Total ratio	1.4 (1.0)	1.1 (0.1)	2.4 (0.2)	2.7 (0.2)	<.001	CU<MCI CU<Dem
Immediate LMT	12.7 (4.8)	14.1 (0.2)	9.2 (0.6)	5.8 (0.7)	<.001	MCI<CU Dem<CU Dem<MCI
Delayed LMT	11.3 (5.3)	13.0 (0.2)	6.1 (0.6)	2.9 (0.7)	<.001	MCI<CU Dem<CU Dem<MCI

Note: CU = cognitively unimpaired; MCI-AD = MCI due to presumed AD; Dementia-AD or Dem = dementia due to presumed AD; LMT = logical memory test; HV = Hippocampal volume; TIV = total intracranial volume; Elapsed time = time elapsed between MRI scan and neuropsychological assessment. P values for the omnibus test or chi-square test.