Table 2. Univariable and multivariable logistic regression analysis for reported bloody diarrhea in cases of Shiga toxin–producing Escherichia coli O157:H7 belonging to the IIb, 250 SNP single linkage cluster 18.% by stx subtype clone, England and Wales, July 2015–December 2017* .

Exposure	No. (%) patients with bloody diarrhea	No. (%) patients without bloody diarrhea
			Univariable analysis			Multivariable analysis†
			OR (95% CI)	p value		OR (95% CI)	p value
stx subtype
stx negative	12 (16.7)	65 (83.3)	Reference			Reference
stx2c	7 (22.6)	29 (77.4)	1.31 (0.47–3.7)	0.61		1.01 (0.35–2.94)	0.978
stx2a	69 (54.3)	69 (45.7)	5.42 (2.69–10.91)	<0.001		4.61 (2.24–9.48)	<0.001
Age
Child, <16 y	22 (20.0)	88 (80.0)	0.28 (0.16–0.50)	<0.001		0.31 (0.17–0.58)	<0.001
Adult, >16 y	66 (46.8)	75 (53.2)	Reference			Reference
Sex
F	55 (40.4)	81 (59.6)	Reference			Reference
M	33 (28.7)	82 (71.3)	0.59 (0.35–1.01)	0.053		0.81 (0.45–1.47)	0.494

*OR, odds ratio; SNP, single-nucleotide polymorphism. 
†Adjusted for each exposure variable (stx subtype, sex, age).