Table 2.
Subgroup analyses based on a random effects model.
| N | Association |
Heterogeneity |
|||
|---|---|---|---|---|---|
| HR (95%CI) | p value | I2 (%) | p value | ||
| Sample size | |||||
| <100 | 6 | 1.94 [1.01; 3.71] | 0.04 | 72.80% | <0.01 |
| ≥100 | 5 | 3.48 [2.41; 5.04] | <0.01 | 53.00% | 0.07 |
| Region | |||||
| Asia | 8 | 2.52 [1.46; 4.35] | <0.01 | 91.90% | <0.01 |
| Europe | 3 | 2.87 [2.00; 4.13] | <0.01 | 0.00% | 0.55 |
| Treatment regimen | |||||
| Mono-Immunotherapy | 7 | 3.35 [2.11; 5.30] | <0.01 | 56.50% | 0.03 |
| Chemoimmunotherapy | 3 | 1.67 [0.77; 3.62] | 0.19 | 91.10% | <0.01 |
| Un-selected | 1 | 3.40 [1.42; 8.13] | – | – | – |
| Line | |||||
| >1 | 1 | 7.28 [0.92; 57.50] | – | – | – |
| 1 | 3 | 1.61 [0.78; 3.29] | 0.20 | 90.60% | <0.01 |
| Un-selected | 7 | 3.35 [2.25; 4.99] | <0.01 | 51.90% | 0.05 |
| Cut-off value | |||||
| <45 | 5 | 1.72 [0.91; 3.24] | 0.09 | 84.60% | <0.01 |
| ≥45 | 6 | 3.62 [2.47; 5.31] | <0.01 | 45.10% | 0.11 |
| Study quality | |||||
| <7 | 6 | 3.01 [1.39; 6.52] | <0.01 | 92.10% | <0.01 |
| ≥7 | 5 | 2.73 [2.11; 3.53] | <0.01 | 0.00% | 0.53 |
HR, hazard ratio; CI, confidence interval.