Dependent variable

Significant independent variables

Odds ratio (95% CI)

p value

Respiratory problem

Smoking^*

3.62 (1.52 - 6.820)

0.003

Duration of employment 24 months or more^†

6.89 (2.35 - 17.32)

0.009

Nasal irritation

Age in years

1.22 (0.99 - 1.48)

0.052

Smoking

5.62 (1.82, 17.34)

0.003

Hoarseness of voice

Age in years

1.32 (1.10, 1.58)

0.002

Smoking

4.39 (1.65, 11.71)

0.003

Duration of employment 12 - 17 months^†

9.85 (1.71, 25.65)

0.001

Tightness of chest

Duration of employment 12 - 17 months^†

9.52 (1.94, 23.72)

0.005

Cough when do not catch cold

Smoking

5.85 (1.67, 20.44)

0.006

Duration of employment 12 - 17 months^†

3.37 ( 1.67, 9.24)

0.003

Bringing up phlegm when do not catch cold

Smoking

6.23 (1.08, 19.52)

0.012

Duration of employment 12 - 17 months^†

4.29 (1.46, 17.24)

0.004

Shortness of breath during hurrying or walking up

Duration of employment 12 - 17 months^†

9.09 (1.48, 34.72)

0.017