Table 2.
Subgroup of OS.
| Subgroup | Heterogeneity | ||||
|---|---|---|---|---|---|
| No of studies | I2 | P values | Pooled HR (95% CI) | P values | |
| Study type | |||||
| Clinical trail | 15 | 32% | 0.11 | 2.18 [1.98, 2.41] | <0.01 |
| Cohort study | 7 | 0% | 0.62 | 3.41 [2.19, 5.31] | <0.01 |
| Race | |||||
| Easterner | 2 | 0% | 0.71 | 1.91 [0.75, 4.83] | 0.17 |
| Westerner | 20 | 33% | 0.07 | 2.23 [2.03, 2.45] | <0.01 |
| Immunotherapy drug | |||||
| anti-PD-1 | 9 | 12% | 0.33 | 2.31 [1.97, 2.72] | <0.01 |
| anti-PD-L1 | 7 | 53% | 0.04 | 2.10 [1.83, 2.41] | <0.01 |
| anti-CTLA-4 | 3 | 0% | 0.54 | 2.16 [1.62, 2.90] | <0.01 |
| anti-PD-1+anti-CTLA-4 | 3 | 20% | 0.29 | 2.86 [2.04, 4.01] | <0.01 |
| sample size | |||||
| ≤30 | 6 | 0% | 0.44 | 3.26 [2.03, 5.24] | <0.01 |
| >30 | 16 | 30% | 0.12 | 2.20 [2.00, 2.42] | <0.01 |