Subgroup analysis | OS | PFS | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
No. of studies | Pooled HR (95% CI) | P value | Heterogeneity | No. of studies | Pooled HR (95% CI) | P value | Heterogeneity | |||
I2 (%) | P | I2 (%) | P | |||||||
Overall | 17 | 2.08 (1.78–2.45) | <  0.00001 | 8 | 0.36 | 8 | 1.51 (1.20–1.91) | 0.0005 | 25 | 0.23 |
Type of PS scale | ||||||||||
 KPS | 6 | 2.20 (1.65–2.94) | <  0.00001 | 24 | 0.26 | 5 | 1.74 (1.19–2.56) | 0.005 | 0 | 0.50 |
 ECOG PS | 11 | 2.03 (1.68–2.46) | <  0.00001 | 6 | 0.39 | 3 | 1.39 (1.04–1.87) | 0.03 | 61 | 0.08 |
Study setting | ||||||||||
 Asia | 6 | 2.25 (1.71–2.95) | <  0.00001 | 26 | 0.24 | 4 | 1.73 (1.14–2.64) | 0.01 | 11 | 0.34 |
 Europe | 8 | 1.95 (1.56–2.43) | <  0.00001 | 28 | 0.20 | 4 | 1.42 (1.08–1.88) | 0.01 | 44 | 0.15 |
 America | 3 | 2.25 (1.43–3.53) | 0.0005 | 0 | 0.93 | 0 | – | – | – | – |
Year of publication | ||||||||||
 Before 2015 | 11 | 1.79 (1.44–2.22) | <  0.00001 | 17 | 0.28 | 6 | 1.51 (1.18–1.94) | 0.001 | 44 | 0.11 |
 After 2015 | 6 | 2.49 (1.97–3.15) | <  0.00001 | 0 | 0.95 | 2 | 1.50 (0.73–3.07) | 0.27 | 0 | 0.56 |
NOS score | ||||||||||
 6 | 5 | 2.07 (1.57–2.74) | <  0.00001 | 28 | 0.24 | 2 | 0.90 (0.54–1.50) | 0.67 | 40 | 0.20 |
 7 | 7 | 1.80 (1.40–2.32) | <  0.00001 | 19 | 0.29 | 4 | 1.57 (1.18–2.10) | 0.002 | 0 | 0.92 |
 8 | 5 | 2.61 (1.92–3.55) | <  0.00001 | 0 | 0.90 | 2 | 2.43 (1.36–4.33) | 0.003 | 0 | 0.43 |