Table 1.

Main characteristic of rheumatoid arthritis (RA) cases and non-cases among male licensed private applicators in the Agricultural Health Study.

Characteristic	Noncases ($n=\mathrm{26},\mathrm{134}$)	Incident RA cases ($n=\mathrm{220}$)
	$n$ (%)	$n$ (%)	ORa (95% CI)
Age at enrollment (years)
$<\mathrm{40}$	7,858 (30)	39 (18)	Reference
40–49	7,956 (30)	72 (33)	1.82 (1.23, 2.70)
50–59	6,035 (23)	75 (34)	2.50 (1.70, 3.69)
$\ge \mathrm{60}$	4,285 (16)	34 (15)	1.60 (1.01, 2.54)
Body mass index ($\mathrm{kg}/{\mathrm{m}}^2$)
$<\mathrm{25}$	6,157 (26)	41 (20)	Reference
25 to $<\mathrm{30}$	12,353 (51)	114 (55)	1.36 (0.95, 1.94)
$\ge \mathrm{30}$	5,551 (23)	51 (25)	1.36 (0.90, 2.06)
State of enrollment
Iowa	17,972 (69)	125 (57)	Reference
North Carolina	8,162 (31)	95 (43)	1.60 (1.22, 2.10)
Race
White	25,454 (97)	212 (96)	Reference
Nonwhite	659 (3)	8 (4)	1.39 (0.69, 2.84)
Education
High school or less	14,117 (54)	137 (62)	Reference
More than high school	12,017 (46)	83 (38)	0.77 (0.58, 1.02)
Smoking status at enrollment
Never smoker	15,046 (58)	100 (45)	Reference
Past smoker	7,637 (29)	74 (34)	1.30 (0.96, 1.78)
Current smoker	3,392 (13)	46 (21)	2.04 (1.44, 2.90)
Pack-years of cigarette smoked
None	15,046 (58)	100 (45)	Reference
$<\mathrm{5}$	3,460 (13)	23 (10)	0.98 (0.62, 1.54)
5–18	3,760 (15)	42 (19)	1.60 (1.11, 2.30)
$>\mathrm{18}$	3,868 (15)	55 (25)	1.95 (1.39, 2.75)
Alcohol consumption (times/wk)
None	8,143 (32)	82 (38)	Reference
$\le \mathrm{1}$	11,778 (47)	84 (39)	0.78 (0.57, 1.07)
$>\mathrm{1}$	5,331 (21)	49 (23)	1.01 (0.70, 1.44)

Note: CI, confidence interval; OR, odds ratio.

^aAdjusted for continuous age.