Table 4.
Subgroup analysis for the association of proton pump inhibitor use with progression-free survival.
| Subgroup | No. of studies | PFS hazard ratios (95% CI) | p-Value | Heterogeneity | |
|---|---|---|---|---|---|
| I2 | p-Value | ||||
| Region | |||||
| America | 4 | 0.85 (0.39–1.84) | 0.683 | 90.2% | <0.001 |
| Europe | 4 | 1.29 (0.98–1.70) | 0.068 | 53.5% | 0.091 |
| Worldwide | 2 | 1.34 (1.20–1.50) | <0.001 | 0% | 0.609 |
| Cancer type | |||||
| NSCLC | 3 | 1.27 (1.10–1.47) | 0.001 | 0% | 0.420 |
| Melanoma | 2 | 0.48 (0.25–0.90) | 0.023 | 31.2% | 0.228 |
| Urothelial carcinoma | 2 | 1.52 (1.13–2.06) | 0.006 | 45.9% | 0.174 |
| Multiple | 4 | 1.23 (0.81–1.85) | 0.326 | 84.4% | <0.001 |
| Age | |||||
| ≤65 | 5 | 0.88 (0.48–1.61) | 0.670 | 87.3% | <0.001 |
| >65 | 5 | 1.32 (1.12–1.56) | 0.001 | 42.2% | 0.140 |
| Sample size | |||||
| ≤200 | 5 | 0.81 (0.46–1.41) | 0.450 | 77.3% | 0.001 |
| >200 | 6 | 1.35 (1.14–1.60) | <0.001 | 69.0% | 0.007 |
| PPI exposure | |||||
| ∞ | 4 | 0.72 (0.40–1.28) | 0.259 | 80.70% | 0.001 |
| ± 30 | 5 | 1.23 (1.06–1.43) | 0.007 | 39.10% | 0.160 |
| Immunotherapy drug | |||||
| PD-1, CTLA-4 | 2 | 0.57 (0.20–1.65) | 0.303 | 77.00% | 0.037 |
| PD-L1 | 2 | 1.34 (1.20–1.50) | <0.001 | 0% | 0.609 |
| ICI | 2 | 1.36 (0.44–4.19) | 0.588 | 91.00% | 0.001 |
| PD-(L)1 | 2 | 1.48 (0.98–2.22) | 0.061 | 66.10% | 0.086 |
NSCLC, non-small cell lung cancer; HR, hazard ratio; PFS, progression-free survival; PD-1, programmed cell death protein-1; PD-L1, programmed cell death ligand 1.