Table 2 Relative risk (RR) and 95% confidence intervals (CIs) of the increase in lung cancer incidence with change in coal capacity, among males and females

 Intercept

3.16 × 10^− 4

(1.82 ~  5.49) × 10^− 4

7.83 × 10^− 5

(0.29 ~  2.09) × 10^− 4

3.20 × 10^− 5

(0.77 ~  13.2) × 10⁻⁵

3.12 × 10^− 5

(0.74 ~  13.2) × 10^− 5

2.82 × 10^− 5

(0.60~13.3) × 10^− 5

 Per capita coal capacity ^a

2.62

(1.40 ~  4.90)

3.88

(2.22 ~  6.78)

1.68

(1.10 ~  2.56)

1.59

(1.07 ~  2.35)

1.57

(1.05~2.35)

 Smoking prevalence ^b

1.03

(1.02 ~  1.05)

1.03

(1.01 ~  1.05)

1.03

(1.01 ~  1.05)

1.03

(1.01~1.06)

 Non-coal capacity ^a

0.94

(0.79 ~  1.12)

0.92

(0.76 ~  1.10)

0.90

(0.73~1.11)

 Traffic index ^b

1.00

(0.98 ~  1.02)

1.00

(0.98 ~  1.02)

1.00

(0.98~1.03)

 Industrialization index ^b

1.03

(1.00 ~  1.05)

1.03

(1.00 ~  1.05)

1.03

(1.00~1.05)

 GDP (PPP) per capita ^c

1.00

(1.00 ~  1.00)

1.00

(1.00 ~  1.00)

1.00

(1.00~1.00)

 Total coal consumption ^d

1.01

(1.00 ~  1.02)

1.01

(1.00 ~  1.02)

1.01

(1.00~1.02)

 QIC

 Intercept

1.03 × 10⁻⁴

(0.58~  1.86) × 10^− 4

1.04 × 10^− 4

(0.49 ~  2.20) × 10^− 4

1.21 × 10⁻⁵

(0.35 ~  4.13) × 10^− 5

1.16 × 10^− 5

(0.34 ~  3.99) × 10^− 5

1.08 × 10^− 5

(0.33~3.57) × 10^− 5

 Per capita coal capacity ^a

3.87

(2.23 ~  6.69)

3.95

(2.71 ~  5.76)

1.84

(1.16 ~  2.93)

1.85

(1.22 ~  2.82)

1.85

(1.22~2.80)

 Smoking prevalence ^b

1.00

(0.96 ~  1.04)

1.02

(1.00 ~  1.05)

1.02

(1.00 ~  1.05)

1.02

(1.00~1.05)

 Non-coal capacity ^a

1.00

(0.80 ~  1.26)

0.99

(0.78 ~  1.24)

0.98

(0.77~1.25)

 Traffic index ^b

1.00

(0.99 ~  1.02)

1.00

(0.99 ~  1.02)

1.00

(0.99~1.02)

 Industrialization index ^b

1.06

(1.023 ~  1.09)

1.06

(1.03 ~  1.10)

1.06

(1.03~1.10)

 GDP (PPP) per capita ^c

1.00

(1.00 ~  1.00)

1.00

(1.00 ~  1.00)

1.00

(1.00~1.00)

 Total coal consumption ^d

1.02

(1.00 ~  1.04)

1.02

(1.01 ~  1.04)

1.02

(1.01~1.04)

 QIC