Table 4.

Farming and risk of hairy cell leukemia (“basic model”)*

	Controls, N (%)	Cases, N (%)	OR (95% CI)†	P
Farming‡
Ever lived or worked on a farm§
No	3362 (59.5)	55 (60.4)	1.00 (referent)	.038
Yes	2215 (39.2)	33 (36.3)	1.68 (1.04 to 2.71)
Ever lived on a farm§
No	1635 (51.4)	33 (64.7)	1.00 (referent)	.384
Yes	1485 (46.7)	13 (25.5)	1.45 (0.63 to 3.34)
Ever worked on a farm§
No	4534 (80.3)	67 (73.6)	1.00 (referent)	.067
Yes	1099 (19.5)	24 (26.4)	1.61 (0.98 to 2.63)
Occupation as a farmer||
Ever worked as a farmer§
No	4564 (80.8)	67 (73.6)	1.00 (referent)	.089
Yes	1081 (19.1)	24 (26.4)	1.55 (0.95 to 2.53)
Duration as a farmer§
Never	4564 (80.8)	67 (73.6)	1.00 (referent)	.184
1–10 y	472 (8.4)	10 (11)	1.32 (0.85 to 3.88)
>10 y	609 (10.8)	14 (15.4)	1.79 (1.50 to 5.93)
Ever worked as a mixed animal and crop farmer§
No	5076 (89.9)	72 (79.1)	1.00 (referent)	.004
Yes	569 (10.1)	19 (20.9)	2.34 (1.36 to 4.01)
Duration as a mixed animal and crop farmer§
Never	5076 (89.9)	72 (79.1)	1.00 (referent)	.009
1–10 y	287 (5.1)	8 (8.8)	1.82 (0.85 to 3.88)
>10 y	282 (5.0)	11 (12.1)	2.98 (1.50 to 5.93)
P trend			0.025

* CI = confidence interval; OR = odds ratio.

† OR (95% CI) adjusted for age, sex, race and/or ethnicity, and study.

‡ Self-reported exposure to farming as a residence or work.

§ The counts do not add up to the total number of cases or controls due to data missing by design or report.

|| Exposure measured from self-reported job history.