Table.

Prevalence of Helicobacter pylori infection in 863 preschool children according to parental history of duodenal or gastric ulcer

			Odds ratio (95% CI)
History of ulcer in parent	No of children	No (%) infected with H pylori	Crude	Adjusted*
Mother:
No	841	112 (13)	1.0	1.0
Yes	22	6 (27)	2.4 (0.9 to 6.4)	11.7 (3.8 to 36.2)
P value for comparison			0.07	<0.0001
Father:
No	835	113 (14)	1.0	1.0
Yes	28	5 (18)	1.4 (0.5 to 3.7)	1.6 (0.4 to 5.5)
P value for comparison			0.51	0.49

^*Adjusted for nationality, mother’s education, father’s education, housing density, birth order, history of breast feeding, attendance at nursery, antibiotic treatment, and history of ulcer in the other parent.