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Table 1 Possible values and characteristics of coal miners with and without CWP

From: Identification and classification of high risk groups for Coal Workers' Pneumoconiosis using an artificial neural network based on occupational histories: a retrospective cohort study

Variable Name

Possible values and number of examples

 

Category

With CWP

(n = 236)

Without CWP

(n = 14419)

χ2(P)

Birth (year of birthday)

(7)Before 1930

52

201

1821.977

(<0.0001)

 

(6)1930-

129

696

 
 

(5)1940-

40

871

 
 

(4)1950-

14

3652

 
 

(3)1960-

1

6168

 
 

(2)1970-

0

2736

 
 

(1)After 1980

0

95

 

Age (age in years of first exposure to dust)

(7)< 20

60

6328

60.003

(<0.0001)

 

(6)20-

100

5786

 
 

(5)25-

51

1614

 
 

(4)30-

16

454

 
 

(3)35-

8

167

 
 

(2)40-

1

61

 
 

(1)≥45

0

9

 

Year (year of first exposure to dust)

(7)Before 1950

14

33

1992.257

(<0.0001)

 

(6)1950-

149

669

 
 

(5)1960-

57

759

 
 

(4)1970-

15

3026

 
 

(3)1980-

1

6164

 
 

(2)1990-

0

3764

 
 

(1)After 2000

0

4

 

Job (occupational category)

(4)Tunneling

201

4949

274.335

(<0.0001)

 

(3)Combining

9

670

 
 

(2)Mining

23

2892

 
 

(1)Helping

3

5908

 

Time 1(years)

Duration of dust exposure

23.38 ± 7.07

18.31 ± 7.05

120.561

(<0.001)

Time 2(years)

Duration of ex-dust exposure

6.09 ± 7.96

2.49 ± 5.72

47.613

(<0.001)

  1. The number of ( ) is possible value of different variables in neural network analysis