Proton pump inhibitors therapy and risk of Clostridium difficile infection: Systematic review and meta-analysis

Table 2 Subgroup analysis

Subgroup analysis	No. of studies(n = 56)	ORs	95%CI	Heterogeneity, I2, %	Heterogeneity between groups, P value
Study design
Case-control	40	2	1.68-2.38	85.54	0.931
Cohort	16	1.98	1.51-2.59	85.99
Study type
Adjusted	38	1.95	1.67-2.27	85.02	0.856
Unadjusted	18	2.02	1.41-2.91	85.58
Centers
Unicentric	31	2.18	1.72-2.75	83.99	0.241
Multicentric	25	1.82	1.51-2.19	86.97
Type
Inpatient	43	1.95	1.67-2.29	84.99	0.868
Outpatient	6	2.1	1.36-3.24	84.84
Mixt	7	2.19	1.39-3.45	76.77
Region
Europe	14	1.78	1.35-2.34	74.33	0.231
America	31	2	1.67-2.40	88.58
Asia	11	2.31	1.96-2.72	89.18
Age
Age < 65 yr	6	2.06	1.11-3.81	35.39	0.86
Age ≥ 65 yr	13	1.93	1.40-2.68	92.11
NOS
NOS ≥ 7	26	1.88	1.55-2.28	87.65	0.441
NOS < 7	30	2.11	1.69-2.62	81.98

CI: Confidence interval; NOS: Newcastle-Ottawa Quality Assessment Scale; ORs: Odds ratio.