TABLE 3.

Propensity score-adjusted antibiotic risk factors for the isolation of ESBL- and non-ESBL-producing Klebsiella species from cases versus controls

Variable (antibiotic exposure)	Bivariate result for the following comparisona:
	ESBL vs control			Non-ESBL vs control
	OR	95% CI	P	OR	95% CI	P
Broad-spectrum cephalosporins	1.89	0.94-3.78	0.07	0.51	0.29-0.87	0.02
Narrow-spectrum cephalosporins	0.74	0.33-1.62	0.45	0.74	0.49-1.11	0.14
Penicillins	4.29	2.23-8.26	<0.01	1.24	0.80-1.91	0.33
β-Lactam-β-lactamase inhibitor combinations	13.48	4.35-41.74	<0.01	2.38	0.93-6.14	0.07
Piperacillin	2.94	0.20-44.13	0.44	1.33	0.17-10.66	0.79
Fluoroquinolones	2.52	1.37-4.64	0.01	0.37	0.25-0.56	<0.01
Aminoglycosides	5.34	2.16-13.18	<0.01	1.44	0.76-2.72	0.26
Clindamycin	2.30	0.75-7.03	0.15	1.64	0.73-3.69	0.23
Metronidazole	2.83	1.53-5.22	<0.01	0.80	0.53-1.20	0.28
Trimethoprim-sulfamethoxazole	1.00	0.32-3.20	1.00	0.44	0.19-1.04	0.06
Carbapenems	0.46	0.07-3.28	0.44	0.32	0.07-1.42	0.13

^aBoldface indicates statistical significance.