Table 1.

Weighted multivariable regression analysis of evaluated predictors of antibiotic resistance.

Bacteria	Variable	Unadjusted	Unadjusted*	Adjusted*
E. coli	Minimum temp	0.512	0.598	0.419
		(<0.0001)	(<0.0001)	(<0.0001)
	Prescription rate	--	0.120	0.121
			(<0.0001)	(<0.0001)
	Outpatient	-3.280	-4.590	-2.980
		(0.14)	(0.09)	(0.06)
	Lab standard	-4.240	-4.900	-3.240
		(0.08)	(0.06)	(0.16)
	Population density	0.00027	0.00035	0.00027
		0.006	(<0.0001)	(0.086)
K. pneumoniae	Minimum temp	0.341	0.397	0.219
		(<0.0001)	(<0.0001)	(<0.0001)
	Prescription rate	--	0.030	0.034
			(<0.0001)	(<0.0001)
	Outpatient	-2.640	-3.006	-2.880
		(0.17)	(0.24)	(0.17)
	Lab standard	-1.760	-2.220	-0.371
		(0.17)	(0.22)	(0.75)
	Population density	0.00051	0.00063	0.0006
		(<0.0001)	(<0.0001)	(<0.0001)
S. aureus	Minimum temp	0.305	0.571	0.273
		(0.002)	(0.004)	(0.21)
	Prescription rate	--	0.133	0.134
			(<0.0001)	(<0.0001)
	Outpatient	-5.800	-5.570	-4.243
		(<0.0001)	(<0.0001)	(0.0003)
	Lab standard	-1.780	-3.450	-3.922
		(0.08)	(0.08)	(0.03)
	Population density	0.00014	0.00015	0.00005
		(0.15)	(0.07)	(0.69)
S. aureus**	Minimum temp	0.405	0.762	0.514
		(<0.0001)	(<0.0001)	(<0.0001)
	Prescription rate	--	0.068	0.066
			(0.0006)	(<0.0001)
	Outpatient	-6.338	-6.520	-4.570
		(0.0005)	(<0.0001)	(0.01)
	Lab standard	-2.305	-4.910	-3.840
		(<0.0001)	(0.008)	(0.01)
	Population density	0.0002	0.0002	0.00004
		(0.035)	(0.009)	(0.27)

Unadjusted and adjusted multivariable regression parameters for historical (30-year) mean minimum temperature (°C), antibiotic class specific prescription rate (annual prescriptions/1000 population), acquisition source (containing outpatient isolates), laboratory standard (CLSI vs. other/not reported), and population density (persons/mi²). P-values are shown in parentheses ().

^*Restricted to subset of antibiotic susceptibilities for dates and classes of antibiotics corresponding to available prescribing rate data.

^**Analysis with Penicillin susceptibility removed.