TABLE 4.

Multivariable model of antibiotic risk factors for the isolation of ESBL-producing Klebsiella spp. after adjustment for propensity score

Variable (antibiotic exposure)	Isolation of ESBL-producing Klebsiella spp.
	OR	95% CI	Pa
Penicillins	1.50	0.65-3.52	0.33
β-Lactam-β-lactamase inhibitor combinations	10.17	1.19-86.92	0.03
Fluoroquinolones	2.86	1.37-5.97	0.01
Aminoglycosides	2.76	0.98-7.77	0.06
Metronidazole	1.74	0.85-3.57	0.13

^aBoldface indicates statistical significance.