TABLE 2.

Comparisons of lengths of stay and treatment outcomes for surviving patients with bloodstream infections caused by gram-negative organisms in the low-, intermediate-, and high-MIC groups

Outcomea	Value for patients (n = 275)f grouped according to:			P valuee
	Low MICb (n = 56)	Intermediate MICc (n = 201)	High MICd (n = 18)
Mortalityf	8 (12.5%)	26 (11.5%)	3 (14.3%)	0.91g
Length of stay postculture (days)	7.3 (6.8)	7.9 (8.8)	16.4 (20.6)h	0.02
Length of levofloxacin treatment postculture (days)	4.8 (4.7)	6.2 (6.2)	13.3 (17.4)i	0.01
Duration of infection (days)	1.0 (0.1)	1.2 (0.8)	2.1 (1.9)j	<0.001

^aAll data are presented as the mean (standard deviation) unless otherwise indicated.

^bA low MIC was defined as a levofloxacin MIC of ≤0.25 mg/liter.

^cAn intermediate MIC was defined as a levofloxacin MIC of 0.5 mg/liter.

^dA high MIC was defined as a levofloxacin MIC of 1 or 2 mg/liter.

^eDetermined by the Kruskal-Wallis test unless otherwise indicated.

^fThe total number of patients including those who died was 312; patients who died were not considered in analyses of outcomes other than mortality.

^gDetermined by a χ² test.

^hResults of Mann-Whitney U nonparametric test for two groups, the high-MIC group versus all others: P = 0.006.

ⁱResults of Mann-Whitney U nonparametric test for two groups, the high-MIC group versus all others: P = 0.02.

^jResults of Mann-Whitney U nonparametric test for two groups, the high-MIC group versus all others: P < 0.001.