Table 3 Summarized HRs of overall and subgroup analyses for DFS

DFS

21

1.894(1.456–2.463)

4.76

< 0.001

78.30%

< 0.001

Random-effect

 Early year(~ 2007)

6

1.428(0.992–2.055)

1.92

0.055

62.10%

0.022

Random-effect

 Later year(2007~ 2016)

15

2.237(1.54–3.249)

4.23

< 0.001

72.00%

< 0.001

Random-effect

 Europe

3

1.023(1.005–1.041)

2.51

0.012

53.40%

0.117

Fixed-effect

 America

4

1.559(1.155–2.105)

2.9

0.004

8.40%

0.351

Fixed-effect

 Asia

14

2.673(2.096–3.409)

7.92

< 0.001

25.60%

0.179

Fixed-effect

 NSCLC

21

1.894(1.456–2.463)

4.76

< 0.001

78.30%

< 0.001

Random-effect

 ADC

9

3.186(1.797–5.650)

3.96

< 0.001

62.10%

0.007

Random-effect

 SQC

2

1.022(1.004–1.04)

2.42

0.015

0.00%

0.774

Random-effect

  < 100

7

2.455(1.392–4.330)

3.10

< 0.001

20.30%

0.28

Fixed-effect

  > 100

14

1.770(1.340–2.338)

4.02

< 0.001

82.80%

< 0.001

Random-effect

 L(< 20%)

12

2.783(2.141–3.619)

7.64

< 0.001

25.30%

0.196

Fixed-effect

 H(≥20%)

6

1.514(1.243–1.844)

4.12

< 0.001

19.40%

0.287

Fixed-effect

 Survival curve

2

1.595(1.053–2.416)

2.21

0.027

52.60%

0.146

Fixed-effect

 HR(univariate)

6

2.126(1.156–3.909)

2.43

0.015

67.40%

0.009

Random-effect

 HR(multivariate)

13

1.892(1.328–2.698

3.53

< 0.001

79.90%

< 0.001

Random-effect