Table 2.
Subgroup analyses of pooled HR for OS.
| Categories | No. of studies | No. of patients | Pooled HR (95% CI) |
Heterogeneity |
||
|---|---|---|---|---|---|---|
| Fix/Random | p-value | I2(%) | P-value | |||
| [1] OS | 23 | 3068 | 1.88 (1.68-2.11) | 0 | 0.2 | 0.458 |
| [2] Cancer type | ||||||
| 1) Colorectal cancer | 3 | 383 | 2.13(1.48-3.05) | 0 | 0 | 0.834 |
| 2) Esophageal cancer | 3 | 314 | 1.15 (0.55-2.37) | 0.712 | 80 | 0.007 |
| 3) Gastric cancer | 3 | 438 | 1.94 (1.42-2.65) | 0 | 11.4 | 0.324 |
| 5) Head and neck cancer | 6 | 741 | 1.77 (1.37-2.29) | 0 | 42.8 | 0.12 |
| 6) Ovarian cancer | 2 | 187 | 1.07 (0.55-2.08) | 0.835 | 31.6 | 0.227 |
| 7) Others | 8 | 1213 | 2.09 (1.76-2.47) | 0 | 0 | 0.43 |
| [3] Analysis | ||||||
| Multivatiate | 21 | 2874 | 1.80 (1.60-2.02) | 0 | 48.9 | 0.006 |
| Survival curves | 2 | 194 | 1.71 (0.93-3.15) | 0.085 | 0 | 0.864 |
| [4] Sample size | ||||||
| ≥115 | 12 | 2079 | 1.85 (1.61-2.13) | 0 | 22 | 0.227 |
| <115 | 11 | 989 | 1.68 (1.21-2.33) | 0.002 | 59.1 | 0.006 |
OS, overall survival; HR, hazard ratio.