Table 3

PRs and 95% CIs of COPD risk spirometry defined as FEV₁/FVC<LLN for exposure to current job codified as four-digit SOC code 2000 in the UK Biobank cohort overall (n=228 614), never-smokers (n=129 858) and non-asthmatics (n=203 086)

		All participants	Never-smokers					Non-asthmatics
SOC code	Occupations	PR	Healthy exposed	Cases exposed	PR	95% CI		Healthy exposed	Cases exposed	PR	95% CI
8217	Seafarers; barge, lighter and boat operatives	2.64	7	3	3.90	1.43	10.65	30	9	3.10	1.79	5.36
8122	Coal mine operatives	2.30	8	0	NA	NA	NA	13	5	3.17	1.37	7.34
9132	Industrial cleaning process occupations	1.96	14	1	1.00	0.13	6.09	33	8	1.96	1.06	3.62
5313	Roofers, roof tilers and slaters	1.86	40	7	1.99	1.00	3.66	95	13	1.53	0.91	2.55
9134	Packers, bottlers, canners, fillers	1.60	81	12	1.67	0.98	2.84	143	21	1.42	0.95	2.13
5112	Horticultural trades	1.55	47	4	1.07	0.42	2.76	81	12	1.51	0.89	2.59
8111	Food, drink and tobacco process operatives	1.46	135	18	1.57	1.02	2.42	274	33	1.45	1.06	2.00
9233	Cleaners, domestics	1.43	905	101	1.38	1.15	1.66	1549	234	1.46	1.29	1.65
5322	Floorers and wall tilers	1.41	95	11	1.46	0.79	2.72	149	22	1.56	1.06	2.30
8114	Chemical and related process operatives	1.39	104	13	1.51	0.90	2.52	200	20	1.32	0.85	2.04
9211	Postal workers, mail sorters, messengers, couriers	1.35	524	58	1.37	1.07	1.75	888	107	1.44	1.19	1.73
9121	Labourers in building and woodworking trades	1.32	159	12	1.01	0.59	1.75	342	47	1.45	1.11	1.89
9244	School mid-day assistants	1.32	244	29	1.42	1.01	2.01	322	37	1.34	0.97	1.85
9223	Kitchen and catering assistants	1.30	487	54	1.34	1.04	1.73	775	98	1.37	1.13	1.66

PRs and 95% CIs for exposure to each four-digit SOC code and COPD risk (defined as FEV₁/FVC<LLN) were calculated by using a Poisson model with robust variance adjusted for sex, study centre (22 categories), age (5 years categories) and lifetime smoking exposure (ever, pack-years and years since quitting). In the analyses among never-smokers, no adjustment for smoking exposure was performed. Reference category: current workers not employed in the specific four-digit SOC-coded job tested. Healthy=non-COPD cases.
COPPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; LLN, lower limit of normal; NA, not available; PR, prevalence ratio; SOC, Standard Occupational Classification.