Table 3 Comparison of HLA DRB1*15 phenotype frequencies.

Comparison	DRB1*15 positive	DRB1*15 negative	OR/RR	(95% CI)	F test	F test
	Number (%)	Number (%)			p	p cor
Controls	88 (35.2)	162 (64.8)	OR	2.646 (1.576 to 4.442)	0.0003	0.0039
ON patients	46 (59.0)	32 (41.0)	RR	1.675 (1.292 to 2.101)
Controls	88 (35.2)	162 (64.8)	OR	4.756 (2.349 to 9.616)	<0.001	<1.0013
ON (MS+) patients	31 (72.1)	12 (27.9)	RR	2.048 (1.559 to 2.482)
Controls	88 (35.2)	162 (64.8)	OR	1.381 (0.680 to 2.804)	0.4527
ON (MS−) patients	15 (42.9)	20 (57.1)	RR	1.218 (0.772 to 1.756)
ON (MS+) patients	31 (72.1)	12 (27.9)	OR	3.444 (1.352 to 8.777)	0.0115
ON (MS−) patients	15 (42.9)	20 (57.1)	RR	1.797 (1.147 to 2.910)
Controls (male)	36 (32.7)	74 (67.3)	OR	1.215 (0.720 to 2.050)	0.5026
Controls (female)	52 (37.1)	88 (62.9)	RR	1.135 (0.809 to 1.607)
ON patients (male)	12 (57.1)	9 (42.9)	OR	1.193 (0.441 to 3.241)	0.7971
ON patients (female)	35 (61.4)	22 (38.6)	RR	1.075 (0.750 to 1.719)

RR, relative risk.