TABLE 3.

Subgroup analysis of Proton Pump Inhibitor Use and the Risk of Gastric Cancer.

Stratified by study design	NO.of studies	PPI users (n)	Non-users (n)	Relative Risk (95% CI)	I2 (%)	p-Value	Heterogenerty, p-value
case-control	3	2,523	17,123	1.52 (1.31.1.76)	19.3	0.289	0.01
Nested case-control	2	2,236	17,769	1.27 (0.94.1.72)	70.3	0.067
Cohort	8	3,029,041	1,363,171	2.15 (1.71.2.70)	88.1	0.000
Events
<1,000	6	69,306	758,866	1.55 (1.23.1.95)	48.4	0.085	0.319
≥1,000	7	2,964,494	639,197	1.88 (1.39.2.56)	96.5	0.000
Population
>10,000	2	1,379	20,690	1.14 (0.91.1.41)	0	0.515	0.001
≤10,000	4	3,498	14,617	1.58 (1.36.1.83)	38.1	0.183
>50,000	7	3,028,923	1,362,756	2.09 (1.65.2.64)	89.8	0.000
Mean age
<65	4	1,007,083	532,255	1.70 (1.25.2.50)	53.2	0.093	0.608
≥65	2	1838	7,689	1.56 (1.34.1.81)	15.1	0.278
Region
Europe	8	2,220,702	1,293,973	1.72 (1.28.2.29)	96	0.000	0.003
Asia	4	15,669	73,041	2.04 (1.58.2.63)	31.9	0.221
America	1	937	10,839	1.07 (0.81.1.42)	0	-
NOS
<7	3	1,179,859	385,832	2.61 (1.48.4.60)	93.6	0	0.136
≥7	10	1,853,941	1.12231	1.59 (1.14.2.20)	95.5	0.000
Lag time
<1 year	2	4,570	67,056	1.66 (1.15.2.40)	53.2	0.144	0.897
≥1 year	10	3,029,112	1,330,592	1.71 (1.31.2.23)	95.3	0.000
Rear of publication
<2010	3	20,531	278,863	1.39 (1.19.1.61)	0	0.573	0.027
≥2010	10	3,013,269	119,200	1.94 (1.50.2.50)	94.4	0.000
Duration of PPI use
<1 year	4	N/A	N/A	1.56 (1.30.1.80)	0	0.486	0.493
1–3 years	3	N/A	N/A	1.75 (1.28.2.37)	0	0.421
>3 years	4	N/A	N/A	2.32 (1.15, 4.66)	75.7	0.006
GC site
cardia	6	N/A	N/A	1.72 (1.19.2.48)	92.5	0.000	0.131
adenocarcinoma	2	N/A	N/A	2.04 (0.73.5.73)	95.4	0.000
non-cardia	6	N/A	N/A	2.75 (2.09.3.62)	89	0.000