. Author manuscript; available in PMC: 2014 Jun 5.

Published in final edited form as: Am J Gastroenterol. 2014 Jan 14;109(3):357–368. doi: 10.1038/ajg.2013.443

Table 5.

Assessment of effect modification

Effect modifier	OR 95% CI among those with the effect modifier(s)^a	OR 95% CI among those without the effect modifier(s)^a	P value likelihood ratio test^b
PPI or H2RA use at least weekly	0.56 (0.27, 1.14)	0.90 (0.49, 1.66)	0.29
Corpus atrophy	0.46 (0.18, 1.18)	0.59 (0.35, 1.01)	0.83
Corpus gastritis	0.88 (0.51, 1.51)	0.33 (0.07, 1.64)	0.18
Corpus gastritis or corpus atrophy	0.82 (0.48, 1.41)	0.33 (0.07, 1.64)	0.21
PPI, H2RA, or corpus atrophy	0.28 (0.15, 0.50)	1.32 (0.66, 2.63)	0.0006
PPI, H2RA, or corpus gastritis	0.37 (0.23, 0.58)	0.95 (0.10, 9.0)	0.45
Any of the above factors	0.37 (0.23, 0.59)	0.97 (0.10, 9.1)	0.45

BE, Barrett's esophagus; CI, confidence interval; H2RA, H2 receptor antagonist; PPI, proton pump inhibitor.

OR for the association between H. pylori infection and BE controlling for age and non-Hispanic White race.

Likelihood ratio test for effect modification using the nested approach.