Table 2.

Diagnostic DSST’s classification between the groups of SCD and aMCI, and aMCI and ADD stratified by age and education.

	DSST Cutoff	AUC	Sensitivity	Specificity	PPV	NPV	p
SCD-MCI
LEL
50–65	---	0.333	---	---	---	---	0.439
66–75	<24	0.761	85.7	65.2	0.59	0.92	0.039
76–85	---	0.700	---	---	---	---	0.157
MEL
50–65	---	0.606	---	---	---	---	0.379
66–75	<38.5	0.825	85.7	84.1	0.67	0.97	<0.001
76–85	---	0.450	---	---	---	---	0.800
HEL
50–65	---	0.651	---	---	---	---	0.141
66–75	<46.5	0.800	0.71	0.78	0.67	0.92	0.001
76–85	---	0.556	---	---	---	---	0.814
MCI-ADD
LEL
50–65	<19.5	0.969	0.83	1.00	0.88	1.00	0.004
66–75	<13.5	0.768	0.74	0.68	0.65	.88	<0.001
76–85	<13.5	0.820	0.75	0.87	0.61	1.00	0.034
MEL
50–65	<25.5	0.922	1.00	0.80	0.77	1.00	<0.001
66–75	<24	0.836	0.75	0.81	0.73	0.93	<0.001
76–85	<21.5	0.823	70	0.82	0.65	0.99	0.002
HEL
50–65	<25.5	1.000	0.97	1.00	1.00	1.00	0.005
66–75	<24	0.767	0.94	0.65	0.60	0.92	0.004
76–85	19.5	0.830	0.89	0.76	0.65	1.00	0.006
SCD-ADD
LEL
50–65	<20	1.000	1.00	1.00	1.00	1.00	0.014
66–75	<20	0.983	1.00	0.91	0.95	1.00	<0.001
76–85	<18	0.962	1.00	0.94	0.91	1.00	0.117
MEL
50–65	<30	0.944	1.00	1.00	0.90	1.00	0.002
66–75	<27.5	0.913	0.92	0.87	0.77	1.00	<0.001
76–85	<19	0.890	1.00	0.71	0.75	1.00	0.026
HEL
50–65	<33.5	1.000	0.91	1.00	1.00	1.00	0.010
66–75	<30.5	0.934	1.00	0.78	0.82	1.00	<0.001
76–85	<24	0.941	1.00	0.88	0.83	1.00	0.046

Abbreviations: DSST: Digit Symbol Substitution Test; SCD: subjective cognitive decline; MCI: mild cognitive impairment; LEL: low educational level; MEL: middle educational level; HEL: high educational level; AUC: Area under the curve; PPV: positive predictive value; NPV: negative predictive value. Note: sensitivity and specificity values are expressed in percentage.