Table 4. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for risk factors independently associated with case status.

Parameter		OR	95% CI	P-value
Non-recommended Antibiotic Use		6.7	2.9, 15.5	<0.01
Comorbidity Severity
	Level 1	0.88	0.30, 2.6	0.82
	Level 2	3.8	1.1, 13.9	0.04
	Level 3	4.0	1.4, 11.7	0.01
Antibiotics given 6 months prior		19.1	8.0, 45.7	<0.01
Surgery Type
	Colorectal	1.4	0.4, 4.7	0.55
	Orthopedic	3.4	1.1, 10.0	0.03
	Vascular, cardiac, thoracic	1.1	0.44, 2.9	0.81
	Neurosurgery	1.2	0.2, 6.4	0.87
	Abdominal, pelvic	Ref	…	…

Ref: reference group.