Table 5.

Military exposures and amyotrophic lateral sclerosis in GENEVA.

	Casesa		Controlsa		IP-weightedb, c
Exposure	No.	%	No.	%	OR	95% CI
Total	619	100	956	100
Ever received the anthrax vaccine prior to reference date	35	7	79	9	1.66	0.87, 3.16
Ever received the smallpox vaccine	468	87	730	87	0.87	0.58, 1.31
Prior to reference date, ever involved in testing, transporting or spraying herbicides for military purposes	18	4	31	3	2.52	1.05, 6.05
Prior to reference date, ever been treated with nasopharyngeal (NP) radium during military service	5	1	5	1	4.45	0.91, 21.72
Ever taken pyridostigmine bromide, or little white pills in foil packs, sometimes called NAPPs, which are used to protect against nerve agents	19	3	23	3	2.70	1.05, 6.96
Prior to reference date, ever visited or resided in the island of Guam, the islands of New Guinea, or the Kii Peninsula of Japan (including any time spent there in the military)	92	16	187	20	0.82	0.53, 1.27
While you were in WWII, the Korean War, the Vietnam War, and/or the Gulf Ward: did you have direct contact with/were you exposed to	231	100	338	100
Ionizing radiation from nuclear weapon testing or occupation of Hiroshima/Nagasaki	< 5e	2	< 5e	1	1.48	0.26, 8.34
Use of personal pesticides, like creams, sprays or flea collars	67	30	102	30	1.47	0.84, 2.57
Use of pesticides on your clothing or bedding	49	23	86	26	1.19	0.64, 2.22
Exhaust from heaters or generators (e.g., kerosene heaters, tent heaters)	75	35	101	30	1.75	1.05, 2.92
Exposure to diesel and/or other petrochemical fumes	145	66	214	64	1.02	0.60, 1.74
Burning trash or burning feces/manure	74	34	130	39	1.06	0.55, 2.04
Exposure to paint, solvents, or petrochemical substances	72	33	118	35	0.78	0.43, 1.40
High-intensity radar waves (e.g., as radar operator, radio operator, aviation electrician’s mate)	45	22	52	17	1.74	0.89, 3.38
Food contaminated with smoke, oil, or other chemicals	15	8	33	11	1.44	0.63, 3.24
Local food other than food provided by the Armed Forces	113	51	169	50	1.21	0.63, 2.34
Bathing in or drinking of water contaminated with smoke, oil, dead animals or any chemicals	21	11	37	12	1.31	0.31, 5.53
Heat cramps, heat exhaustion, heat stroke or other heat illness	51	23	84	25	1.47	0.74, 2.90
Heard chemical alarms sounding	15	7	33	10	0.95	0.43, 2.10
Explosion in the air or on the ground within one mile of you (e.g., artillery, rockets, mortars)	151	68	210	64	1.87	1.11, 3.14
Have you suffered a combat-related injury that required medical attention during your deployment?	50	22	77	23	1.47	0.73, 2.98
While you were in WWII, the Korean War, and/or the Vietnam Ward: did you have direct contact with/were you exposed to	219	100	314	100
Mixing and application of herbicides	5	2	< 5e	1	3.58	0.56, 23.06
Exposure to herbicides in the field	12	7	14	6	2.37	0.62, 9.02
Mixing and application of riot control substances	< 5e	1	7	2	2.65	0.33, 21.14
Exposure to riot control substances in the field	13	6	26	8	1.43	0.48, 4.24
Mixing and application of burning agents	15	7	6	2	7.75	1.92, 31.24
Exposure to burning agents in the field	34	16	31	10	1.50	0.42, 5.30
While you were in the Korean War, the Vietnam War, and/or the Gulf Ward: did you have direct contact with/were you exposed to	196	100	327	100
Microwave radiation	14	8	24	8	1.25	0.50, 3.11
While you were in the Vietnam Ward, f: did you have direct contact with/were you exposed to	127	100	219	100
Mixing and application of Agent Orange	8	7	13	6	1.15	0.38, 3.44
Exposure to Agent Orange in the field	58	59	77	44	2.80	1.44, 5.44
While you were in the Gulf Ward: did you have direct contact with/were you exposed to	16	100	30	100
Use of depleted uranium (DU) for munitions or armor	5	38	< 5e	15	4.12	0.67, 25.22
CARC (Chemical Agent Resistant Compound) paint	< 5e	29	< 5e	17	3.88	0.64, 23.40
Scud missile explosion in the air or on the ground within one mile of you	< 5e	31	11	39	4.31	0.70, 26.77
Smoke from oil well fires	9	64	20	69	1.16	0.23, 5.74
Exposure to nerve gas (e.g., during munitions destruction)	< 5e	21	< 5e	5	g	g
High levels of dust/sand	13	81	28	93	0.78	0.10, 5.89
Ground level fumigation	< 5e	31	< 5e	8	8.54	1.05, 69.70
In any conflicts deployed to, any other exposure or experience not asked about which you consider harmful or extremely stressful	75	24	108	31	0.82	0.49, 1.37

Abbreviation: ALS, amyotrophic lateral sclerosis; ALSFRS-R, ALS Functional Rating Scale-Revised; BIRLS, Beneficiary Identification and Records Locator System; CARC, Chemical Agent Resistant Compound; CI, confidence interval; DU, depleted uranium; GENEVA, Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis; Gulf, 1990–1991 Persian Gulf; IP, inverse probability; NP, nasopharyngeal; OR, odds ratio; VA, Department of Veterans Affairs; WWII, World War II.

^aInformation for specific exposures was missing for 0–49% of cases and 0–63% of controls.

^bCases and controls who did not experience direct contact with each specific exposure were the reference.

^cWeighted for confounding (condtional on age [centered at age 60—the median age among controls—and modeled with linear and quadratic terms], use of the VA health care system, sex, race/ethnicity, and military branch of longest service), not missing baseline ALSFRS-R score (cases only: conditional on most recent ALS diagnosis category, symptom onset site, time from symptom onset to diagnosis [months; modeled with the natural logarithm of a linear term], and time from diagnosis to enrollment in the Registry [months; modeled with a restricted, quadratic spline with knots at 7.72, 13.24, 23.06, and 44.19 months based on percentiles of the distribution in the Registry cases not missing baseline ALSFRS-R score]), and participating in GENEVA (cases: conditional on race/ethnicity, being a current patient of a VA Medical Center, most recent ALS diagnosis category, symptom onset site, time from symptom onset to diagnosis [months; modeled with linear, quadratic, and cubic terms], time from diagnosis to enrollment in the Registry [months; modeled with a linear term], and baseline ALSFRS-R score [modeled with a restricted, quadratic spline with knots at 12, 34, and 44 based on percentiles of the distribution in GENEVA cases]; controls: conditional on year of birth [modeled with a restricted, quadratic spline with knots at 1920, 1947, and 1974 based on percentiles of the distribution in the BIRLS potential controls], use of the VA health care system, and their interaction). War deployment-related exposures were not weighted for sex because of model instability. 95% CIs were calculated with robust variance estimates.

^dThe GENEVA study questionnaire asked “Were you deployed to…” the following wars where each war was asked about with a separate question: World War II (defined as the period from December 7, 1941, to December 31, 1946), the Korean War (defined as the period from June 27, 1950, to January 31, 1955), the Vietnam War (defined as the period from August 3, 1964, to May 7, 1975), and the Persian Gulf War (defined as the period from August 2, 1990, to December 31, 1991).

^eSuppressed to preserve the confidentiality of study participants.

^fRestricted analyses to veterans who were born between 1939 and 1957 inclusive (i.e., they were 18–25 years old at the time of the Vietnam War, or 1964–1975) because doing so drastically improved the behavior of the IP weights used for analysis. This restriction resulted in the exclusion of 21 (14%) cases and 51 (19%) controls.

^gUnable to estimate OR and 95% CI.