Table 1. Demographic and clinical characteristics of the total sample.

Variables	ONFH patients (n = 23)	controls (n = 20)	p value
Age (y)	55.61 ± 13.79	47.25 ± 19.35	0.12*
Men (n,%)	14(60.9)	12(60.0)	0.95#
Education (years)	12.48 ± 2.84	12.30 ± 3.18	0.85*
Operation history(n,%)	5(21.7)	4(20)	1.00#
Hypertension(n,%)	2(8.7)	2(10)	1.00#
Diabetes(n,%)	3(13)	2(10)	1.00#

Notes.

^*using two-sample t-test.

^#using x² test.