A Prospective Study of Lupus and Rheumatoid Arthritis in Relation to Deployment in Support of Iraq and Afghanistan: The Millennium Cohort Study

Table 1

Baseline* characteristics of Millennium Cohort participants with newly reported lupus and rheumatoid arthritis (2001–2008).

Characteristics	Lupus				Rheumatoid arthritis
	Disease		No disease		Disease		No disease
	𝑛=115		n = 72,576		n = 1,100		n = 69,924
	𝑛	%^†	𝑛	%^†	𝑛	%^†	𝑛	%^†
Deployment^‡
Nondeployed	75	65.2	39,874	54.9	744	67.6	38,111	54.5
Deployed without combat	22	19.1	17,985	24.7	174	15.8	17,594	25.2
Deployed with combat^§	18	15.7	14,717	20.3	182	16.6	14,219	20.3
Sex
Male	56	48.7	51,240	70.6	760	69.1	49,321	70.5
Female	59	51.3	21,336	29.4	340	30.9	20,603	29.5
Birth year
Before 1960	22	19.1	13,686	18.9	381	34.6	12,629	18.1
1960–1969	41	35.7	24,131	33.3	470	42.7	22,996	32.9
1970–1979	41	35.7	24,020	33.1	197	17.9	23,645	33.8
1980 and later	11	9.6	10,739	14.8	52	4.7	10,654	15.2
Race/ethnicity
Non-Hispanic white	58	50.4	51,610	71.1	673	61.2	49,882	71.3
Non-Hispanic black	32	27.8	8,723	12.0	244	22.2	8,214	11.8
Hispanic	13	11.3	4,883	6.7	90	8.2	4,718	6.8
Other	12	10.4	7,360	10.1	93	8.5	7,110	10.2
Education
High school or less	67	58.3	37,153	51.2	572	52.0	35,815	51.2
Some college	25	21.7	15,797	21.8	297	27.0	15,061	21.5
Bachelor’s or higher degree	23	20.0	19,626	27.0	231	21.0	19,048	27.2
Marital status
Married	66	57.4	42,522	58.6	793	72.1	40,514	57.9
Not married	49	42.6	30,054	41.4	307	27.9	29,410	42.1
Service component
Active duty	64	55.7	40,745	56.1	640	58.2	39,235	56.1
Reserve/Guard	51	44.4	31,831	43.9	460	41.8	30,689	43.9
Military pay grade
Enlisted	97	84.4	55,262	76.1	935	85.0	53,068	75.9
Officer	18	15.7	17,314	23.9	165	15.0	16,856	24.1
Service branch
Army	63	54.8	33,856	46.7	619	56.3	32,349	46.3
Air Force	30	26.1	21,557	29.7	272	24.7	20,924	29.9
Marine Corps	4	3.5	3,880	5.4	43	3.9	3,765	5.4
Navy/Coast Guard	18	15.7	13,283	18.3	166	15.1	12,886	18.4
Occupation
Combat specialist	16	13.9	14,058	19.4	185	16.8	13,588	19.4
Health care specialist	23	20.0	8,259	11.4	90	8.2	8,054	11.5
Functional support	33	28.7	14,085	19.4	291	26.5	13,428	19.2
Electrical/mechanical	12	10.4	10,156	14.0	155	14.1	9,744	13.9
Service support	10	8.7	6,433	8.9	125	11.4	6,139	8.8
Other	21	18.3	19,585	27.0	254	23.1	18,971	27.1
Body mass index (kg/m^2)
Normal/underweight (<25)	56	48.7	29,520	40.7	320	29.1	28,790	41.2
Overweight (25 to <30)	45	39.1	35,874	49.4	604	54.9	34,441	49.3
Obese (≥30)	14	12.2	7,182	9.9	176	16.0	6,693	9.6
Smoking status
Nonsmoker	68	59.1	42,572	58.7	552	50.1	41,285	59.0
Past smoker	21	18.3	17,425	24.0	321	29.2	16,613	23.8
Current smoker	26	22.6	12,579	17.3	228	20.7	12,026	17.2
Alcohol misuse^¶
No	91	79.1	58,901	81.2	894	81.3	56,766	81.2
Yes	24	20.9	13,675	18.8	206	18.7	13,158	18.8
Mental component score
>75th percentile	26	22.6	20,760	28.6	299	27.2	19,974	28.6
>50th to 75th percentile	27	23.5	17,759	24.5	248	22.6	17,166	24.6
>25th to 50th percentile	23	20.0	16,266	22.4	182	16.6	15,721	22.5
0 to 25th percentile	39	33.9	17,791	24.5	371	33.7	17,063	24.4
Physical component score
>75th percentile	20	17.4	20,307	28.0	124	11.3	19,756	28.3
>50th to 75th percentile	26	22.6	18,245	25.1	168	15.3	17,664	25.3
>25th to 50th percentile	22	19.1	17,135	23.6	256	23.3	16,552	23.7
0 to 25th percentile	47	40.9	16,889	23.3	552	50.2	15,952	22.8
Chemical and/or biological warfare agents
No	106	92.2	68,750	94.7	968	88.0	66,446	95.0
Yes, 1 or more times	9	7.8	3,826	5.3	132	12.0	3,478	5.0
Hazards requiring personal protective equipment
No	65	56.5	31,622	43.6	476	43.3	30,558	43.7
Yes	46	40.0	39,420	54.3	584	53.1	37,921	54.2
Do not know	4	3.5	1,534	2.1	40	3.6	1,445	2.1
Routine skin contact with paint, solvents, substances
No	74	64.4	50,431	69.5	669	60.8	48,912	70.0
Yes	33	28.7	19,276	26.6	363	33.0	2,719	3.9
Do not know	8	7.0	2,869	4.0	68	6.2	2,719	3.9
Microwaves (excluding microwave ovens)
No	83	72.2	53,942	74.3	718	65.3	52,253	74.7
Yes	24	20.9	12,818	17.7	232	21.1	12,165	17.4
Do not know	8	7.0	5,816	8.0	150	13.6	5,506	7.9
Pesticides (creams, sprays, uniform treatments)
No	71	61.7	46,506	64.1	606	55.1	45,091	64.5
Yes	35	30.4	19,652	27.1	378	34.4	18,709	26.8
Do not know	9	7.8	6,418	8.8	116	10.6	6,124	8.8
Pesticides (environment, living facilities)
No	63	54.8	42.194	58.1	523	47.6	40,985	58.6
Yes	37	32.2	20,508	28.3	410	37.3	19,462	27.8
Do not know	15	13.0	9,874	13.6	167	15.2	9,477	13.6

*Population excludes participants with missing baseline covariates, may not represent whole study population.
^†Percentages may not sum to 100 because of rounding.
^‡ Deployed in support of the operations in Iraq and Afghanistan.
^§ Self-report of personally witnessing or being exposed to a person’s death due to war or disaster, physical abuse, dead and/or decomposing bodies, maimed soldiers or civilians, prisoners of war, or refugees.
^¶Alcohol misuse is defined as at least 1 positive response to the CAGE questions (i.e., Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers) [32, 33].