Table 3. Relation between S. aureus surgical site infections and risk factors for SSI.

Factor		Univariate			Multivariate
	RR	95% CI	P-value	RR	95% CI	P-value***
Duration of the surgical procedure	NA		0.62**	1.0	0.98–1.02	0.89
ASA class 1 or 2 (compared to >2)	2.9	0.4–21.5	0.29*	3.4	0.4–30.2	0.26
BMI	NA		0.99**	1.0	0.88–1.34	0.89
S. Aureus screening	9.8	1.1–88.6	0.039*	12.8	1.1–147.9	0.041

^*Fisher exact test;

^**t-test;

^***Chi-square.