Table 4 Relationships between duration and time since first employment and asthma, and bronchitis symptoms adjusted for age, sex, smoking and SES expressed as Odds Ratios (OR) with 95% confidence interval in parenthesis (95% CI) ¹.

Construction

Duration ≤ 20 yrs

0.75 (0.15–3.75)

1.84 (0.56–6.55)

Duration >20 yrs

1.43 (0.34–6.09)

2.25 (0.69–7.38)

Time since first employment ≤18 yrs

0.71 (0.15–3.34)

1.56 (0.47–5.23)

Time since first employment >18 yrs

1.65 (0.36–7.52)

2.86 (0.78–10.51)

Metal

Duration ≤ 6 yrs

0.65 (0.18–2.40)

0.53 (0.18–1.59)

Duration >6 yrs

3.85 (0.98–15.13)#

5.28 (1.53–18.25)**

Time since first employment ≤ 20 yrs

0.95 (0.25–3.66)

0.80 (0.25–2.55)

Time since first employment >20 yrs

2.03 (0.55–7.55)

2.54 (0.80–8.05)

Rubber, plastics, and synthetics

Duration ≤ 9 yrs

2.01 (0.31–13.21)

1.57 (0.28–8.98)

Duration >9 yrs

5.81 (1.13–29.78)*

6.40 (1.51–27.20)*

Time since first employment ≤ 23 yrs

3.71 (0.74–8.61)

2.92 (0.65–13.14)

Time since first employment >23 yrs

3.80 (0.36–25.73)

5.21 (1.02–26.51)

Printing

Duration ≤ 4 yrs

1.14 (0.23–5.38)

1.47 (0.44–4.96)

Duration >4 yrs

1.17 (0.19–7.11)

2.38 (0.62–9.05)

Time since first employment ≤ 16 yrs

0.83 (0.14–5.11)

1.44 (0.38–5.50)

Time since first employment >16 yrs

1.57 (0.27–8.95)

2.66 (0.76–9.27)