Table 4.

Associations between FeNO >50 ppb and occupational exposure in respondents with COPD

Occupational exposure	OR (95% CI)
Mineral dusts exposure
Non-exposure	Reference
Short-term	1.724 (0.670, 4.438)
Intermediate	0.770 (0.290, 2.040)
Long-term	0.315 (0.131, 0.760)
Organic dusts
Non-exposure	Reference
Short-term	1.238 (0.431, 3.555)
Intermediate	0.452 (0.159, 1.290)
Long-term	0.115 (0.034, 0.395)
Exhaust fumes
Non-exposure	Reference
Short-term	0.685 (0.220, 2.132)
Intermediate	1.377 (0.390, 4.854)
Long-term	0.168 (0.058, 0.489)
Other fumes
Non-exposure	Reference
Short-term	1.067 (0.400, 2.841)
Intermediate	0.178 (0.035, 0.901)
Long-term	0.573 (0.165, 1.985)

Note: Significant values are shown in bold (P<0.05).

Abbreviations: FeNO, fractional exhaled nitric oxide; COPD, chronic obstructive pulmonary disease; OR, odds ratio; CI, confidence interval.