Table 3.

Multivariate final model^a of risk factors that influence the likelihood of Salmonella being detected in a produce field (based on testing of soil and drag swab samples)

Factor	Description	β coefficient	SE	OR	95% CI	P value
Manure	Last time manure was applied to field
	Within 365 days	2.8	0.9	16.7	3.0, 94.4	0.002
	Over 365 days	0.3	1.1	1.3	0.2, 11	0.789
	Not applied	0		1.0
Buffer zoneb	Does field have a buffer zone
	Yes	−2.0	0.7	0.1	0.03, 0.6	0.008
	No	0		1.0
Farm	Random effect	1.6	1.5

^aFinal model developed in PROC GLIMMIX, with farm as random effect.

^bA buffer zone was defined as a strip of land where no produce was grown, at least approximately 5 m wide.