Table 3.

Sensitivity analysis of association between crude oil exposures and acute neurologic symptoms, excluding responders with pre-existing specific neurologic conditions.

Acute neurological symptom	Exposure level	Inhalation								Skin contact
		All active duty (N = 1638)				Active duty - no pre-existing conditions (N = 1626)				All active duty (N = 1117)				Active duty - no pre-existing conditions (N = 1107)
		N^a	PR (adj.)^b	(9a5% CI)	p-Trend	N^a	PR (adj.)^b	(95% CI)	p-Trend	N	PR (adj.)^b	(95% CI)	p-Trend	N	PR (adj.)^b	(95% CI)	p-Trend
Headaches	Never	368	1.00			338				530				585	1.00
	Rarely	282	1.30	(1.14–1.47)		258	1.22	1.10–1.36		312	1.28	1.16–1.37		335	1.37	(1.24–1.52)
	Sometimes	297	1.62	(1.43–1.84)		277	1.48	1.36–1.67		181	1.41	1.30–1.53		199	1.55	(1.39–1.73)
	Most/all times	244	1.81	(1.59–2.08)	< 0.0001	219	1.61	1.44–1.80	< 0.0001	69	1.36	1.22–1.57	< 0.0001	72	1.57	(1.38–1.78)	< 0.0001
Lightheadedness/dizziness	Never	85	1.00			83				146				150	1.00
	Rarely	84	1.52	(1.12–2.04)		82	1.51	1.19–1.90		105	1.54	1.28–1.86		111	1.68	(1.32–2.12)
	Sometimes	106	2.25	(1.69–3.00)		96	2.15	1.71–2.70		90	2.19	1.79–2.68		97	2.65	(2.09–3.36)
	Most/all times	129	3.60	(2.70–4.80)	< 0.0001	125	2.78	2.17–3.56	< 0.0001	45	2.59	2.00–3.36	< 0.0001	46	3.46	(2.56–4.67)	< 0.0001
Difficulty concentrating	Never	74	1.00			73				127				128	1.00
	Rarely	61	1.27	(0.91–1.78)		61	1.10	0.87–1.39		60	1.16	0.933–1.44		60	1.12	(0.83–1.51)
	Sometimes	66	1.66	(1.19–2.33)		66	1.23	0.96–1.58		58	1.65	1.29–2.11		58	2.05	(1.50–2.80)
	Most/all times	61	1.96	(1.36–2.83)	0.0001	61	1.36	1.36–1.83	< 0.0001	16	1.11	0.69–1.77	0.0001	16	1.67	(0.99–2.81)	0.0001
Numbness/tingling sensation	Never	29	1.00			26				48				52	1.00
	Rarely	25	1.29	(0.74–2.23)		22	1.27	0.85–1.89		30	1.35	0.97–1.87		31	1.33	(0.85–2.09)
	Sometimes	35	2.20	(1.30–3.71)		35	1.89	1.27–2.82		33	2.10	1.46–3.02		35	2.84	(1.80–4.49)
	Most/all times	38	3.20	(1.86–5.51)	< 0.0001	37	2.53	1.64–3.90	< 0.0001	9	1.82	1.00–3.32	0.0002	9	2.19	(1.02–4.67)	< 0.0001
Blurred/double vision	Never	33	1.00			27				38				47	1.00
	Rarely	23	1.13	(0.65–1.96)		17	1.28	0.84–1.95		19	1.17	0.78–1.74		26	1.39	(0.86–2.26)
	Sometimes	24	1.48	(0.84–2.58)		18	1.32	0.83–2.09		27	2.69	1.81–3.99		34	3.62	(2.27–5.77)
	Most/all times	38	3.17	(1.86–5.42)	< 0.0001	33	2.41	1.51–3.86	< 0.0001	11	2.25	1.16–4.34	< 0.0001	11	3.38	(1.70–6.75)	< 0.0001
Memory loss/confusion	Never	18	1.00			18				30				30	1.00
	Rarely	14	1.15	(0.56–2.35)		14	0.97	0.57–1.65		18	1.31	0.85–2.04		18	1.35	(0.75–2.43)
	Sometimes	25	2.52	(1.32–4.81)		25	1.90	1.15–3.11		22	2.11	1.28–3.49		22	3.18	(1.75–5.76)
	Most/all times	19	2.35	(1.12–4.95)	0.004	19	1.45	0.78–2.69	0.0037	6	1.66	0.69–4.00	0.0015	6	2.25	(0.83–6.12)	0.0015

With the outcome and exposure.

Adjusted for: age, sex, dispersant contact, exhaust exposure, smoking, heat index and hours of sleep per night during deployment.