Table 4.

Analysis of variance: in the final model, the length of hospital stay before the operation and stroke were independently associated with surgical site infection after the operation to correct femoral fractures. Preoperative length of hospital stay greater than four days increased the chance that a patient would be infected almost threefold (OR = 3.3; p = 0.037) (July 2007–July 2009).

Variable	Regression coefficient	Standard error of the regression coefficient	Odds ratio	p value
Preoperative length of hospital stay greater than 4 days	1.19	0.57	3.3	0.037
Stroke	1.60	0.62	5	0.009
Constant	−3.96	0.52