TABLE 2.

Association between length of hospital stay, antimicrobial therapy, and ARE colonization in hospitalized patients by univariate analysis (study A)

Characteristic	No. (%) of patients		OR	95% CI	P value
	ARE	No ARE
Patients studieda	181	645
Length of hospital stay (days)
1–2b	14	141	1.0	0.4–2.3	1.0
3–7	35	167	2.1c	1.1–4.3	0.02
8–14	39	135	2.9c	1.5–5.9	<0.001
>14	93	202	4.6c	2.5–8.9	<0.001
>5 days treatment withd:
Any antibiotice	110 (61)	164 (25)	4.7c	3.3–6.7	<0.001
Cephalosporins	28 (15)	39 (6)	2.9c	1.7–5.0	<0.001
Fluoroquinolones	24 (13)	36 (5)	2.7c	1.5–4.7	<0.001
Penicillins	27 (16)	35 (5)	3.1c	1.8–5.5	<0.001
Carbapenems	10 (6)	19 (3)	2.0f	0.9–4.6	0.08
Macrolides	9 (5)	5 (<1)
Metronidazole	9 (5)	14 (2)
Glycopeptides	5 (6)	9 (3)

^aData are missing for 15 patients. 

^bOne to 2 days was defined to represent basic risk of colonization. 

^cSignificant OR. 

^dDuring preceding 2 weeks. 

^eAlso significant by logistic regression analysis (adjusted OR, 3.8; P < 0.001, see text). 

^fNonsignificant OR.