Table 2 Pooled HR of PD-L1 expression (high vs. low level) for OS and PFS according to subgroup analyses
Outcomes | Study number | Model | Test of association | Heterogeneity | ||
|---|---|---|---|---|---|---|
HR (95% CI) | P value | I2 (%) | P-H | |||
PFS | 11 | Random | 1.897 (1.160, 3.104) | 0.011 | 88.2 | 0.000 |
IHC scoring systems | ||||||
 TPS (≥ 50% vs. < 50%) | 5 | Random | 3.020 (2.298, 3.968) | 0.000 | 8.9 | 0.356 |
 Moderate staining (≥ 5% vs. < 5%) | 2 | Random | 0.832 (0.503, 1.379) | 0.476 | 51.5 | 0.151 |
 TC (TC3 vs. TC0) | 1 | Random | 5.263 (3.308, 9.116) | 0.000 | / | / |
 H scoresa (≥mean vs. <mean) | 3 | Random | 1.106 (0.391, 3.130) | 0.850 | 84.8 | 0.001 |
Sample size | ||||||
 > 100 | 3 | Random | 2.864 (2.058, 3.987) | 0.000 | 2.1 | 0.360 |
 < 100 | 8 | Random | 1.628 (0.869, 3.049) | 0.128 | 89.9 | 0.000 |
IHC antibodies | ||||||
 22C3 | 3 | Random | 2.956 (1.938, 4.510) | 0.000 | 34.2 | 0.219 |
 SP263 | 2 | Random | 1.933 (0.511, 7.315) | 0.331 | 94.5 | 0.000 |
 28-8 | 1 | Random | 2.439 (1.342, 4.433) | 0.003 | / | / |
 SP142 | 2 | Random | 4.858 (3.016, 7.827) | 0.000 | 0.0 | 0.566 |
 E1L3N | 1 | Random | 0.930 (0.517, 1.672) | 0.808 | / | / |
 ab58810 | 2 | Random | 0.511 (0.323, 0.807) | 0.004 | 0.0 | 0.621 |
Survival analysis mode | ||||||
 Multivariate analysis | 6 | Random | 1.844 (0.911, 3.733) | 0.089 | 86.4 | 0.000 |
 Univariate analysis | 5 | Random | 1.964 (0.895, 4.308) | 0.092 | 91.7 | 0.000 |
Countries | ||||||
 China | 4 | Random | 1.508 (0.538, 4.224) | 0.434 | 92.2 | 0.000 |
 Italy | 1 | Random | 0.580 (0.294, 1.130) | 0.116 | / | / |
 Japan | 3 | Random | 2.173 (0.837, 8.580) | 0.111 | 90.9 | 0.000 |
 Korea | 3 | Random | 3.346 (2.303, 4.860) | 0.000 | 0.0 | 0.622 |
OS | 9 | Random | 1.186 (0.986, 1.427) | 0.070 | 86.1 | 0.000 |
IHC scoring systems | ||||||
 TPS (≥ 50% vs. < 50%) | 3 | Random | 2.945 (1.471, 5.894) | 0.002 | 67.2 | 0.048 |
 Moderate staining (≥ 5% vs. < 5%) | 2 | Random | 1.127 (0.637, 1.994) | 0.682 | 63.5 | 0.064 |
 H scoresa (≥mean vs. <mean) | 3 | Random | 0.657 (0.296, 1.458) | 0.302 | 78.7 | 0.009 |
Sample size | ||||||
 > 100 | 3 | Random | 2.945 (1.471, 5.894) | 0.002 | 67.2 | 0.048 |
 < 100 | 6 | Random | 0.985 (0.888, 1.093) | 0.774 | 66.4 | 0.011 |
IHC antibodies | ||||||
 22C3 | 2 | Random | 2.191 (0.901, 5.330) | 0.084 | 62.4 | 0.103 |
 SP263 | 2 | Random | 1.855 (0.283, 12.157) | 0.520 | 94.0 | 0.000 |
 E1L3N | 2 | Random | 1.601 (0.487, 5.266) | 0.439 | 67.5 | 0.079 |
  SP142 | 1 | Random | 1.001 (0.991, 1.012) | 0.852 | / | / |
 ab58810 | 2 | Random | 0.548 (0.147, 2.036) | 0.369 | 89.2 | 0.002 |
Survival analysis mode | ||||||
 Multivariate analysis | 6 | Random | 1.201 (0.668, 2.160) | 0.540 | 80.7 | 0.000 |
 Univariate analysis | 3 | Random | 1.499 (0.986, 1.427) | 0.441 | 93.7 | 0.000 |
Countries | ||||||
 China | 4 | Random | 1.238 (0.370, 4.145) | 0.730 | 87.3 | 0.000 |
 Italy | 1 | Random | 1.000 (0.986, 1.427) | 1.000 | / | / |
 Japan | 1 | Random | 0.699 (0.334, 1.463) | 0.342 | / | / |
 Korea | 3 | Random | 1.884 (0.634, 5.361) | 0.261 | 93.6 | 0.000 |