Table 3. Subgroup analyses of survival outcomes based on different factors.
| Subgroup | No. of studies (No. of patients) | HR (95%CI) | Model | Heterogeneity | Significance (P) | Meta-regression (P) | |
|---|---|---|---|---|---|---|---|
| I 2 | P | ||||||
| Total | 7 (678) | 1.587(1.175–2.144) | Fixed | 0.00% | 0.814 | 0.003 | |
| Sample size | 0.913 | ||||||
| >100 | 2 (328) | 1.558 (0.998–2.432) | Fixed | 0.00% | 0.564 | 0.051 | |
| <100 | 5 (350) | 1.612 (1.073–2.422) | Fixed | 0.00% | 0.624 | 0.022 | |
| Cut-off value | 0.321 | ||||||
| >1% | 5 (547) | 1.682 (1.219–2.320) | Fixed | 0.00% | 0.815 | 0.002 | |
| >5% | 2 (131) | 1.065 (0.458–2.475) | Fixed | 0.00% | 0.523 | 0.884 | |
| PD-L1 expression score | 0.744 | ||||||
| TPS | 6 (626) | 1.593 (1.178–2.152) | Fixed | 0.00% | 0.722 | 0.002 | |
| CPS | 1 (52) | 0.750 (0.008–67.903) | - | - | - | 0.9 | |
| Type of PD-L1 expression | 0.578 | ||||||
| tissue microarrays | 1 (219) | 1.310 (0.625–2.744) | - | - | - | 0.474 | |
| whole tissue section | 6 (459) | 1.649 (1.187–2.291) | Fixed | 0.00% | 0.753 | 0.003 | |
| HR estimation | 0.726 | ||||||
| calculated | 3 (278) | 1.719 (1.005–2.940) | Fixed | 0.00% | 0.924 | 0.048 | |
| reported | 4 (400) | 1.531 (1.065–2.200) | Fixed | 0.00% | 0.443 | 0.021 | |
HR, hazard ratio; TPS, tumor proportion score; CPS, combined positivity score; CI: confidence interval.