Table 1.

Group size and gender information are reported for each class.

	${\mathcal{D}}_{train}$		${\mathcal{D}}_{test}$			Total
Disease status	AD (38)	NC (29)	AD (48)	NC (52)	cMCI (48)	215
Female/male	18/20	13/16	22/26	25/27	21/27	99/116
Age (years)	73.55 ± 8.00	74.97 ± 6.30	78.41 ± 6.02	74.77 ± 6.01	76.12 ± 5.89	75.56 ± 6.44
Education (years)	15.29 ± 3.43	16.93 ± 2.78	15.42 ± 3.13	16.37 ± 2.98	15.33 ± 3.03	15.87 ± 3.07
MMSE	22.68 ± 2.27	29.07 ± 0.92	24.32 ± 1.89	28.97 ± 0.81	26.78 ± 1.77	26.36 ± 1.53
n sites	23	19	26	29	18	34

The table also provides age, years of education and MMSE (mean and standard deviation). The disease status reported is referred at the baseline visit. According to t-test statistics, MMSE scores resulted significantly different with a p-value p < 0.01 for all comparisons except those between ${\mathcal{D}}_{train}$ and ${\mathcal{D}}_{test}$ normal controls and between ${\mathcal{D}}_{train}$ and ${\mathcal{D}}_{test}$ AD patients.