Table 3.

The comparison of ABO blood groups in patient and control groups (The reference for each group is all other 3 groups for ABO blood groups) (OR: Odds ratio).

	Patient (n/%)	Control (n/%)	OR	P	95% CI
A	106 (57)	716 (38)	2.1 (1.5–2.9)	<0.001	1.84–1.89
B	20 (10.8)	277(14.7)	1.4 (0.8–2.3)	0.155	1.90–1.96
AB	14 (7.5)	188 (10)	1.3 (0.7–2.3)	0.364	1.89–1.96
O	46 (24.8)	701 (37.2)	1.8 (1.2–2.5)	0.001	1.92–1.95
Rh–	26 (14)	174 (9.2)	ref		ref
Rh+	160 (86)	1708 (90.8)	1.2 (0.9–1.4)	0.321	1.86–1.91