Acid suppressive drugs and gastric cancer: A meta-analysis of observational studies

Table 2 Association between acid suppressive drugs use and gastric cancer risk in subgroup meta-analysis

Category	No. of studies	Adjusted OR/RR (95%CI)	Heterogeneity, I2 % (95%CI)	Model used	Heterogeneity between groups
Type of drugs					P = 0.01
H2RAs	10[23-27,52-55,57]	1.40 (1.24-1.59)	59.5 (19.0-80.0)1	Fixed-effects
PPIs	3[54,55,57]	1.39 (1.19-1.64)	0.0 (0.0-90.0)	Fixed-effects
Location of gastric cancer					P = 0.03
GE junction	2[24,26]	2.28 (0.97-5.35)	0.0 (NA)	Fixed-effects
Gastric cardia	4[52,54-56]	0.88 (0.63-1.24)	9.2 (0.0-86.0)	Fixed-effects
Non-cardia	6[24,26,52,54-56]	1.42 (1.12-1.79)	0.0 (0.0-75.0)	Fixed-effects
Duration of drugs use					P = 0.27
Within 5 yr	7[23,24,26,27,52,55,57]	1.58 (1.35-1.81)	60.2 (9.0-83.0)1	Fixed-effects
Over 5 yr	6[23,24,26,27,52,57]	1.24 (0.84-1.84)	25.4 (0.0-69.0)	Fixed-effects
Study quality					P = 0.01
High-quality2	6[52,53,54,55-57]	1.34 (1.21-1.48)	0.0 (0.0-75.0)	Fixed-effects
Low-quality	5[23-27]	1.86 (1.49-2.32)	63.5 (4.0-86.0)1	Fixed-effects

¹I² value greater than 50% represents substantial heterogeneity. We conducted sensitivity analyses by removing each study to determine the studies that contributed most to the heterogeneity;

²High quality study was considered a study awarded 7 or more stars, as standard criteria have not been established. OR: Odds ratio; RR: Relative risk; H₂RAs: Histamine 2-receptor antagonists; PPIs: Proton pump inhibitors; GE junction: Gastroesophageal junction; NA: Not available.