Table 7. Combined multilevel analysis of participant- and farm-based characteristics associated with Coxiella burnetii seropositivity in dairy cattle farm residents, the Netherlands, September 2010–March 2011*.

Variable	OR (95% CI)
Age, y
<35	Reference
35–44	1.3 (0.8–2.3)
45–54	1.2 (0.7–2.0)
>55	1.9 (1.1–3.5)
Work on farm
No	Reference
Part time (1–39 h/wk)	2.5 (1.1–5.6)
Full time (>40 h/wk)	10.7 (4.2–27.0)
Use of gloves during cattle birth care
Fully compliant	0.4 (0.2–0.8)
Partly or noncompliant	Reference
No birth care	0.7 (0.4–1.1)
Contact with pigs at own or other farm
Yes	2.4 (1.1–5.1)
No	Reference
Contact with poultry at own farm
Yes	0.5 (0.3–0.8)
No	Reference
Indirect contact with rats/mice at own farm
Yes	1.6 (1.0–2.7)
No	Reference
No. cows on farm in 2008†	1.0 (1.0–1.0)
Farm region
South	1.9 (1.2–3.1)
Other	Reference
Automatic milking
Yes	0.6 (0.4–1.0)
No	Reference
Birds in stable
Yes	2.3 (1.2–4.4)
No	Reference
Contact with cows at other farm
Yes	1.8 (1.0–3.2)
No	Reference
Contact with compost
Yes	0.6 (0.3–0.9)
No	Reference
Beef cattle on the farm
Yes	1.9 (1.0–3.7)
No	Reference

*The analysis included the primary participant- and farm-based characteristics associated with positivity (p<0.10 in likelihood ratio test). The number of observations was 708; the number of levels used was 309 (quasi-likelihood under the independence model criterion 695.52). OR, odds ratio.
†Risk increases per cow.