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Table 3 Results of meta-regression analyses

From: Occupational exposure to silica dust and risk of lung cancer: an updated meta-analysis of epidemiological studies

Measure

Parameter

k

Estimate

P value estimate

P value of Q

I2

R2

p covariates

Meta-regression analysis of SMR studies

 SMR

No covariate

63

1.55 (1.38–1.75)

<0.0001

<0.0001

96.18

  

 Univariate model

Year of publication

63

2.30E + 18 (2.41E + 08–2.19E + 28)

0.003

<0.0001

95.44

15.12

0.000

Industry

63

1.15 (0.86–1.53)

0.353

<0.0001

95.71

8.15

0.027

Person-years of follow-up

22

1.53 (1.25–1.87)

<0.0001

<0.0001

94.73

13.4

0.050

NOS score

63

3.53 (2.27–5.49)

<0.0001

<0.0001

95.11

19.18

0.000

Number of subjects

63

1.69 (1.48–1.92)

<0.0001

<0.0001

95.43

10.89

0.008

Total number of deaths

54

1.69 (1.48–1.94)

<0.0001

<0.0001

95.31

13.94

0.006

 Multivariate model

Industry, year of publication

63

1.07E + 19 (3.85E + 09-2.97E + 28)

<0.0001

<0.0001

94.65

25.51

<0.0001

Industry, year of publication, geographical location

63

1.04E + 20 (4.90E + 10-2.21E + 29)

<0.0001

<0.0001

94.3

28.85

<0.0001

Industry, year of publication, geographical location, number of subjects

63

1.80E + 17 (1.67E + 08-1.94E + 26)

<0.0001

<0.0001

93.18

37.41

<0.0001

Industry, year of publication, geographical location, number of subjects, NOS score

63

1.06E + 16 (5.27E + 06-2.12E + 25)

0.001

<0.0001

93.05

37.04

<0.0001

Industry, year of publication, geographical location, number of subjects, total deaths

54

5.32E + 18 (1.07E + 08-2.65E + 29)

0.001

<0.0001

92.72

34.76

<0.0001

Industry, year of publication, geographical location, NOS score

63

1.29E + 17 (3.61E + 07-4.61E + 26)

<0.0001

<0.0001

93.77

32.23

<0.0001

Person-years of follow-up, industry

22

1.22 (0.76–1.96)

0.408

<0.0001

94.12

13.87

0.086

Person-years of follow-up, industry, year of publication

22

2.80E + 14 (2.88E-08-2.73E + 36)

0.198

<0.0001

92.81

17.99

0.079

Person-years of follow-up, industry, year of publication, geographical location

22

1.55E + 23 (4.66E-02-5.12E + 47)

0.064

<0.0001

92.31

23.08

0.056

Person-years of follow-up, number of subjects

22

1.62 (1.31–2.00)

<0.0001

<0.0001

92.9

17.36

0.055

Meta-regression analysis of SIR studies

 SIR

No covariate

19

1.68 (1.45–1.96)

<0.0001

<0.0001

74.51

  

 Univariate model

Year of publication

19

7.92E + 11 (3.71E-02-1.69E + 25)

0.080

<0.0001

72.31

4.27

0.086

Industry

19

1.37 (0.97–1.95)

0.077

<0.0001

70.88

11.68

0.214

Number of subjects

19

1.88 (1.55–2.28)

<0.0001

<0.0001

69.94

18.16

0.086

Total number of deaths

5

1.29 (1.05–1.59)

0.017

0.687

0

100

0.017

 Multivariate model

Number of subjects, exposure level

19

2.09 (1.47–2.96)

<0.0001

<0.0001

72.12

9.02

0.197

 

Number of subjects, NOS score

19

3.01 (1.52–5.95)

0.002

<0.0001

69.36

15.16

0.087

 

Number of subjects, industry

19

1.71 (1.03–2.85)

0.037

<0.0001

70.28

10.84

0.229

Meta- regression of silicotic studies

 SMR

Year of publication

24

7.03E + 21 (5.05E + 04-9.79E + 38)

0.013

<0.0001

92.23

20.55

0.014

Year of publication, total number of deaths

20

1.59E + 23 (1.60E + 05-1.57E + 41)

0.012

<0.0001

86.98

42.87

0.002

Year of publication, total number of deaths, geographical location, industry

20

4.61E + 22 (2.40E + 03-8.85E + 41)

0.021

<0.0001

86.9

33.84

0.022

Year of publication, total number of deaths, industry

20

6.07E + 22 (1.43E + 04-2.58E + 41)

0.017

<0.0001

87.46

38.8

0.002

Year of publication, total number of deaths, geographical location

20

9.89E + 22 (2.24E + 04-4.37E + 41)

0.016

<0.0001

86.65

38.3

0.007

Year of publication, geographical location

24

1.26E + 22 (3.90E + 04-4.08E + 39)

0.013

<0.0001

92.05

16.98

0.050

  1. k number of studies, Q chi-square test for heterogeneity, I 2 variability due to heterogeneity, R 2 amount of heterogeneity accounted for, SMR standardized mortality ratio, SIR standardized incidence ratio, NOS Newcastle-Ottawa scale