Skip to main content
. 2016 Jun 10;124(11):1728–1734. doi: 10.1289/EHP129

Table 3.

Field work and other farm exposures in relation to incident RA cases for female spouses in the Agricultural Health Study.

Tasks and other farm exposures Incident cases
Noncases n= 24,018 n (%) Cases n = 132 n (%) OR (95% CI)a
Worked in the field recent growing season
No 11,132 (48) 71 (55) 1.0 (referent)
< 10 days 4,766 (20) 22 (17) 0.78 (0.48, 1.3)
10–30 days 4,183 (18) 23 (18) 0.89 (0.55, 1.4)
> 30 days 3,235 (14) 13 (10) 0.63 (0.35, 1.4)
Tasksb
Till soil 5,740 (25) 27 (22) 0.88 (0.57, 1.4)
Planting 5,538 (24) 40 (32) 1.3 (0.91, 2.0)
Apply natural fertilizer 2,700 (12) 13 (11) 0.85 (0.48, 1.5)
Apply chemical fertilizer 2,540 (11) 23 (18) 1.7 (1.1, 2.7)
Drive combines 2,545 (11) 11 (9) 0.86 (0.46, 1.6)
Handpick crops 5,909 (25) 37 (29) 1.1 (0.75, 1.7)
Other tasks, at least monthlyb
Drive trucks 8,942 (39) 42 (35) 0.88 (0.59, 1.3)
Drive diesel tractor 7,727 (34) 33 (27) 0.77 (0.49, 1.1)
Drive gas tractor 5,956 (26) 32 (26) 1.0 (0.65, 1.5)
Clean with gasoline 3,440 (15) 18 (15) 1.0 (0.61, 1.7)
Clean with solvents 4,522 (20) 33 (27) 1.6 (1.1, 2.4)
Painting 7,246 (32) 45 (37) 1.3 (0.91, 1.9)
Veterinary procedures 2,927 (13) 13 (11) 0.99 (0.55, 1.8)
Hours per day in the sun, recent growing season
< 1 4,678 (26) 32 (29) 1.0 (referent)
1 to 2 5,769 (33) 42 (39) 1.1 (0.72, 1.8)
3 to 5 5,047 (29) 26 (24) 0.82 (0.49, 1.4)
≥ 6 2,127 (12) 9 (8) 0.67 (0.32, 1.4)
Hours per day in the sun, 10 years ago
< 1 2,940 (18) 13 (14) 1.0 (referent)
1 to 2 4,391 (26) 30 (28) 1.4 (0.75, 2.6)
3 to 5 5,724 (35) 44 (42) 1.6 (0.86, 2.8)
≥ 6 3,506 (21) 16 (15) 0.89 (0.44, 1.8)
Regular livestock contact, past 12 monthsc
Never 10,820 (46) 60 (54) 1.0 (referent)
Infrequent 6,765 (29) 35 (27) 0.99 (0.65, 1.5)
Frequent 5,699 (24) 24 (19) 0.82 (0.51, 1.3)
Livestock exposure, in childhoodc
None 4,752 (27) 33 (29) 1.0 (referent)
Infrequent 2,469 (14) 13 (11) 0.81 (0.42, 1.6)
Frequent 10,589 (59) 68 (60) 0.87 (0.57, 1.3)
Any childhood and current livestock exposure
Neither 3,754 (21) 28 (25) 1.0 (referent)
Childhood only 9,256 (52) 70 (61) 0.96 (0.62, 1.5)
Current only 998 (6) 5 (4) 0.84 (0.32, 2.2)
Childhood and current 3,802 (21) 11 (10) 0.48 (0.24, 0.97)
aLogistic regression models adjusted for age, state and pack-years smoking, estimated ORs and 95% CI. bReferent group was an answer of “no” for each task. cInfrequent is less than once per week, and frequent is at least weekly.