Table 2 Results of overall and subgroup analyses for effects of initiation of adjuvant chemotherapy for > 8 weeks on survival in patients with colorectal cancer

Overall survival

18

160,134

1.37 (1.27, 1.48)

7.97

 < 0.001

87.80

 < 0.001

Region

 Asian countries

3

51,877

1.75 (1.35, 2.27)

4.22

 < 0.001

0.00

0.448

 Non-Asian countries

15

108,257

1.35 (1.24, 1.46)

7.31

 < 0.001

89.50

 < 0.001

Tumor site

 Colon

9

95,677

1.39 (1.26, 1.54)

6.45

 < 0.001

90.30

 < 0.001

 Rectum

3

15,136

1.25 (1.11, 1.41)

3.62

 < 0.001

79.40

0.008

Sample size

  < 1000

6

3009

1.53 (1.12, 2.09)

2.67

0.008

69.00

0.006

  ≥ 1000

12

157,125

1.37 (1.26, 1.49)

7.52

 < 0.001

91.10

 < 0.001

Study quality

  < 6

7

70,943

1.32 (1.19, 1.48)

5.12

 < 0.001

90.00

 < 0.001

  ≥ 6

11

89,191

1.45 (1.26, 1.65)

5.42

 < 0.001

86.40

 < 0.001