Table 4.

Multi-Variable Logistic Analysis

Independent variable	Odds ratio	se	z ratio	Prob.	95% CI
Antibiotic days (quartiles)
8–11 d	0.252	0.130	−2.65	0.008	0.091	0.698
12–18 d	0.162	0.090	−3.28	0.001	0.055	0.481
19–185 d	0.313	0.136	−2.68	0.007	0.134	0.732
Site
A	6.50	3.40	3.58	<0.001	2.33	18.096
B	5.35	2.33	3.84	<0.001	2.27	12.587
APACHE II	1.09	0.020	4.71	<0.001	1.053	1.133
Constant	0.025	0.015	−6.26	<0.001	0.008	0.080

Model χ² = 48.68.

Pseudo R² = 0.177.

n = 335.

CI = confidence interval; APACHE = Acute Physiology and Chronic Health Evaluation.

Referents for independent variables were 1–7 days for antibiotics and Site C.

The dependent variable in this model is death resulting from necrotizing soft-tissue infections, coded so that 0 = lived and 1 = died.