Table 1

Prevalence and occupational association of COPD among never-smoking Danes, N=1575

	LLN							GOLD 2+
	Cases	Total		Crude OR		Adjusted* OR		Cases	Total		Crude OR		Adjusted* OR
	n	n	(%)	OR	95% CI	OR	95% CI	N	n	(%)	OR	95% CI	OR	95% CI
VGDF occupational exposure†
No exposure	8	831	1.0	1.00	Reference	1.00	Reference	17	831	2.1	1.00	Reference	1.00	Reference
Any VGDF exposure	15	655	2.3	2.41	(1.02 to 5.72)	3.69	(1.36 to 10.04)	29	655	4.4	2.22	(1.21 to 4.07)	3.23	(1.55 to 6.73)
Organic dust occupational exposure‡
No exposure	8	733	1.1	1.00	Reference	1.00	Reference	16	733	2.2	1.00	Reference	1.00	Reference
Any organic exposure	13	562	2.3	2.15	(0.88 to 5.21)	2.94	(1.05 to 8.22)	27	562	4.8	2.26	(1.21 to 4.24)	2.79	(1.32 to 5.93)

Beyond the significance level of 5% is presented in bold.
*Mixed random effect logistic regression model adjusted for: age group: 45–54, 55–64, 65–74 and 75–84 years of age; sex; general practitioner practice (random variable).
†Missing values: VGDF exposure n=80, spirometry n=7, VGDF and spirometry n=2.
‡Missing values: organic dust exposure n=271, spirometry n=6, organic dust and spirometry n=3.
COPD, chronic obstructive pulmonary disease; GOLD 2+, Global Initiative for Chronic Obstructive Lung Diseases, defined as fixed forced expiratory volume 1 s (FEV₁)/forced vital capacity (FVC) ratio<0.70 and FEV₁< 80% of the predicted value; LLN, lower limit of normal, defined as FEV₁/FVC z-score <2 SDs and FEV₁ z-score <2; VGDF, vapour, gas, dust and fume.