Table 2. Comparison of classification performance of feature and sample selection (in %).

Selection	AD vs. NC		MCI vs. NC		pMCI vs. sMCI
	ACC	AUC	ACC	AUC	ACC	AUC
Sample only	88.9†	95.1†	74.9†	80.7†	76.2†	84.5†
Feature only	91.3*	96.4*	77.3†	85.0†	78.1†	85.9†
Sample + Feature	92.4	97.4	80.1	87.2	80.8	88.3

Symbol ^† indicates p < 0.01 in the t-test as compared to the proposed method, and * means p < 0.05.