Table 5 Subgroup meta-analysis of pooled HRs for OS
Stratified analysis | Studies (n) | Number of patients | Pooled HR (95% CI) | P-value | Heterogeneity | ||
|---|---|---|---|---|---|---|---|
I2% | P-value | Model | |||||
NOS score | |||||||
  ≥ 7 | 8 | 1192 | 3.480 (2.447,4.948) |  < 0.001 | 0.0% | 0.515 | Fixed |
  < 7 | 3 | 339 | 3.198 (1.966,5.201) |  < 0.001 | 0.0% | 0.475 | Fixed |
Follow-up time | |||||||
  ≥ 60 | 10 | 1471 | 3.427(2.556,4.595) |  < 0.001 | 0.0% | 0.572 | Fixed |
  < 60 | 1 | 60 | 2.660(0.780,9.070) | 0.118 |  |  |  |
Cancer type | |||||||
 Respiratory system | 2 | 222 | 3.483 (1.939,6.258) |  < 0.001 | 0.0% | 0.653 | Fixed |
 Nervous system | 2 | 141 | 2.392 (1.060,5.398) | 0.036 | 0.0% | 0.390 | Fixed |
 Digestive system | 2 | 158 | 10.770 (0.260,11.840) | 0.098 | 69.8% | 0.069 | Fixed |
 Urinary system | 2 | 177 | 2.900 (1.275,6.600) | 0.011 | 28.9% | 0.236 | Fixed |
 Other systems | 3 | 833 | 3.972 (2.600,6.067) |  < 0.001 | 0.0% | 0.790 | Fixed |
Sample size | |||||||
  ≥ 60 | 9 | 1426 | 3.564 (2.634,4.823) |  < 0.001 | 0.0% | 0.612 | Fixed |
  < 60 | 2 | 105 | 3.380 (2.542,4.496) | 0.069 | 0.0% | 0.527 | Fixed |