Table 3 Risk factors for chronic airway obstruction (CAO) and COPD

 < 40 years

Reference

Reference

40–60 years

1.51

(0.77–2.94)

1.68

(0.79–3.58)

 > 60 years

4.08

(2.13–7.81)

3.73

(1.77–7.87)

Male sex

0.98

(0.67–1.43)

0.97

(0.64–1.46)

University education

Reference

Reference

Non-university edu

1.07

(0.72–1.59)

1.02

(0.66–1.57)

Never-smoker

Reference

Reference

 ≤ 10 packyears

1.18

(0.70–1.98)

1.28

(0.71–2.29)

11–20 packyears

2.37

(1.37–4.11)

2.51

(1.35–4.67)

21–30 packyears

3.98

(2.26–7.01)

5.01

(2.73–9.19)

 > 30 packyears

6.53

(3.84–11.10)

7.54

(4.24–13.42)

Exp to GDF at work

1.36

(0.91–2.01)

1.50

(1.01–2.36)