Table 5 Cohort studies of refinery work and non-Hodgkin’s lymphoma (NHL)

Author, year (Reference)	RR	CI_low	CI_up	N	Location	Exposure	Outcome	All cause SMR	Adj RR	Adj CI_low	Adj CI_up
Collingwood et al 199651	0.71	0.09	2.57	2	Paulsboro, New Jersey	Employed 30+ years	LR SMR	0.93	0.76	0.07	2.19
Consonni et al 199952	2.12	0.68	4.95	5	Northern Italy	Total cohort	NHL SMR	0.87	2.46	0.78	5.08
Dagg et al 199253	0.55	0.01	3.05	1	Chevron, El Segundo	Employed 30+ years	LR SMR	0.73	0.75	0.00	2.94
Dagg et al 199253	2.26	0.97	4.45	8	Chevron, Richmond	Employed 30+ years	LR SMR	0.86	2.71	1.16	4.90
Divine et al 199954	0.3	0.1	0.7	5	Texaco Mortality Study	Employed 30+ years	LR SMR	0.79	0.38	0.12	0.78
Gun et al 200611	0.99	0.62	1.50	22	Health Watch	Total cohort (men)	NHL SMR	0.72	1.38	0.87	2.02
Honda et al 199555	0.96	0.51	1.64	13	Illinois refinery	Hourly	LR SMR	0.82	1.17	0.62	1.89
Huebner et al 200456	1.46	0.86	2.3	18	Exxon Mobile, Baton Rouge	Employed 30+ years	NHL SMR	0.79	1.86	1.10	2.82
Huebner et al 200456	0.66	0.27	1.36	7	Exxon Mobile, Baytown	Employed 30+ years	NHL SMR	0.79	0.83	0.33	1.57
Kaplan 198657	0.9	0.51	1.46	16	US refinery workers, TCA, API	Total cohort	LR SMR	0.78	1.15	0.66	1.79
Lewis et al 200058	1.09	0.68	1.65	22	Canada, Exxon Mobile	Total cohort (men)	NHL SMR	0.92	1.19	0.74	1.73
Pukkala 199859	2.01	1.00	3.59	11	Finland	Blue collar workers	NHL incidence	na*	na	na	na
Satin et al 199660	0.27	0.03	0.97	2	Gulf/Chevron, Pt Arthur	Employed 30+ years	LR SMR	0.88	0.31	0.03	0.87
Sorahan et al 200228	1.22	0.97	1.51	84	8 British oil refineries	Total cohort (men)	LR SMR	0.88	1.39	1.11	1.70
Thomas et al 198261	1.57	0.75	2.89	10	OCAW	Retired	NHL PMR	na*	na	na	na
Tsai et al 199362	1.21	0.15	4.37	2	Shell, Martinez	Total cohort	LR SMR	0.89	1.36	0.13	3.90
Tsai et al 199627	6.75	2.48	14.69	6	Shell, Deer Park	Employed 30+ years	LR SMR	1.04	6.91	2.49	13.55
Tsai et al 200363	2.32	0.48	6.79	3	Norro, LA	Total cohort	LR SMR	0.74	3.15	0.59	7.71
Waxweiler et al 198364	0.68	0.18	1.74	4	Texas City	Hourly	LR SMR	0.8	0.85	0.22	1.89
Wong et al 2001a65	1.16	0.24	3.40	3	Mobil, Beaumont	Employed 30+ years	NHL SMR	0.94	1.24	0.23	3.04
Wong et al 2001b66	1.14	0.24	3.35	3	Mobil, Torrance	Hired 40+ years ago	NHL SMR	0.91	1.25	0.24	3.07

Adj, adjusted for the healthy worker effect; CI_low, lower 95 CI; CI_up, upper 95 CI; exposure, the exposure category selected for this meta-analysis; LR, lymphosarcoma and reticulosarcoma; N, number of cases in the selected exposure category; PMR, proportionate mortality ratio; SMR, standardised mortality ratio; self-report, “Yes” means exposure history based primarily on self-reported work history.
*The healthy worker effect adjustment was not done because data were not available on all cause mortality (Pukkala 1998) or the study was a proportionate mortality study (Thomas et al 1982).