The Correlation between the Use of the Proton Pump Inhibitor and the Clinical Efficacy of Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer

Table 4

The subgroup analysis of the correlation between the use of PPI and clinical efficacy of ICIs for progression-free survival.

Subgroup	No. of studies	PFS hazard ratios (95% CI)	value	Heterogeneity
				I^2 (%)	value
Region
Worldwide	2	1.34 [1.16, 1.55]	<0.001	0	0.4
Asia	1	0.91 [0.54, 1.54]	0.72	NA	NA
Europe	2	1.36 [1.18, 1.57]	<0.001	0	0.99
Oceania	2	1.12 [0.78, 1.60]	0.54	86.00	0.008
Age
≤65	2	1.23 [0.75, 2.00]	0.41	63.00	0.1
>65	2	1.36 [1.18, 1.57]	<0.001	0	0.99
Sample size
≤300	3	1.31 [1.00, 1.71]	0.05	25.00	0.26
>300	4	1.23 [1.04, 1.44]	0.01	71.00	0.01
Immunotherapy drug
PD-L1	2	1.33 [1.19, 1.49]	<0.001	0	0.69
PD-1	1	1.36 [0.89, 2.07]	0.15	NA	NA
PD-1, other	1	0.91 [0.54, 1.54]	0.72	NA	NA
PD-(L)1	3	1.17 [0.73, 1.88]	0.52	85.00	0.009
PPI exposure
−30	1	1.51 [1.11, 2.05]	0.008	NA	NA
±30	5	1.32 [1.20, 1.45]	<0.001	0	0.71
∞	1	0.93 [0.76, 1.13]	0.47	NA	NA

PFS, progression-free survival; PD-1, programmed cell death protein-1; PD-L1, programmed cell death ligand 1; HR, hazard ratio; NA, not available.