Table 1.

Sociodemographic characteristics of diagnostic subgroups

Variable	HC	SCD	MCI	AD	∑
	n = 33	n = 68	n = 301	n = 220	N = 622
Age (years) *** Mdn (IQR)	59.8 ± 7.7 58 (54–65.5)	69.6 ± 9.5 70.5 (63.5–76)	69.6 ± 9.2 71 (63.5–76.5)	74.2 ± 8.1 76 (70–79)	70.7 ± 9.4 73 (65–77)
Education (years)*** Mdn (IQR)	14.9 ± 4.4 14 (10.5–19)	12.6 ± 3.9 12 (9–16)	12.7 ± 4.2 12 (9–16)	11.0 ± 3.4 10 (8–13)	12.2 ±4
					12 (8–16)
Sex female	22 (66.7%)	34 (50.0%)	156 (51.8%)	125 (56.8%)	337 (54.2%)
Male	11 (33.3%)	34 (50.0%)	145 (48.2%)	95 (43.2%)	285 (45.8%)

HC Healthy controls, SCD Subjective cognitive decline, MCI Mild cognitive impairment, AD Alzheimer’s dementia, Mdn Median, IQR Interquartile range, Age and years of education are reported as mean ± standard deviation and Mdn (IQR), means were compared using Kruskal–Wallis test for age and years of education

***p < 0.001