. 2018 Oct 29;80(12):1853–1860. doi: 10.1292/jvms.18-0287

Table 2. Results of univariable and multivariable general linear regression models (n=38).

Independent variables		Dependent variables, Standardized coefficients (β)

		LOG total oral antimicrobial usage		LOG doxycycline usage		LOG amphenicols usage		LOG penicillins usage		LOG macrolides usage		LOG fluoroquinolones usage

		Univariable	Multivariable	Univariable	Multivariable	Univariable	Multivariable	Univariable	Multivariable	Univariable	Multivariable	Univariable	Multivariable
Site external biosecurity	1. Site conditions	−0.439^c)	−0.342^b)	−0.441^c)		−0.472^c)		−0.504^c)	−0.441^c)	−0.347^b)		−0.252^a)
	2. Replacement gilts	−0.142		−0.178		−0.336^b)		−0.108		−0.188		−0.194
	3. Employee	−0.359^b)		−0.163		−0.385^b)		−0.125		−0.38^b)		−0.182
	4. Transport vehicles	−0.334^b)		0.043^a)		−0.177		−0.302^a)		−0.369^b)		−0.205
	5. Manure & carcass	−0.268^a)		−0.392^b)		−0.306^a)		−0.255^a)		−0.356^b)		−0.274^a)
	6. Vermin controls	−0.398^b)		−0.331^b)		−0.355^b)		−0.272^a)		−0.302^b)		−0.102
	7. Farm contractors	−0.438^c)	−0.342^b)	−0.184		−0.449^c)		−0.257^a)		−0.496^c)	−0.33^b)	−0.272^a)

Internal biosecurity	8. Pen layouts	−0.336^b)		−0.456^b)		−0.654^c)	−0.372^b)	−0.393^b)		−0.507^c)	−0.352^b)	−0.369^a)
	9. Pig flows	−0.25^a)		−0.423^c)	−0.36^b)	−0.542^c)	−0.284^b)	−0.396^b)	−0.306^b)	−0.368^b)		−0.558^c)	−0.558^c)
	10. Cleaning & disinfection	−0.102		−0.148		−0.247^a)		0.12		−0.199		−0.187
	11. Employee	0.032		0.178		−0.087		0.078		−0.196		0.099
	12. Injection needles	−0.185		−0.02		−0.19		−0.208		−0.178		−0.172
	13. Delivery stalls	0.004		0.035		0.01		−0.108		0.109		−0.147

Animal welfare indicators	14. Density of fattening pig	0.084		−0.014		−0.048		−0.294^a)		0.123		−0.129
	15. Pre-weaning mortality risk	0.187^a)		0.33^b)		0.367^b)		0.097		0.282^a)		0.129
	16. Post-weaning mortality risk	0.15		0.501^c)	0.45^c)	0.516^c)	0.344^c)	0.247^a)		0.256^a)		0.079

	Adjusted R²		0.26		0.342		0.537		0.306		0.304		0.292
	Power of test		0.943		0.989		1		0.976		0.975		0.971

LOG: log transformed. Values with a–c indicate that these variables are significantly associated with antimicrobial usage with P-values <0.2, <0.05, and <0.01 respectively. Independent variables in boldface indicate that they are significantly associated with antimicrobial usage in two or more multivariable models. Adjucted R² values in boldface indicate multivariable models that have more than two independent variables significantly associated with the antimicrobial usage.