Table 4.

Risk ratio (RR) for PJI in patients with SSSI

SSSI—no progression to PJI	60 (71%)
SSSI—progression to PJI	24 (29%)
Variable		Crude RR (95% CI)	P value	Adjusted RR (95% CI)	P value
Joint
Hip		Ref		Ref
Knee		1.1 (0.4 to 2.9)	0.836	1.3 (0.4 to 3.6)	0.663
Age
<65		Ref		Ref
≥65		1.5 (0.6 to 3.9)	0.404	2.0 (0.7 to 6.2)	0.212
ASA class
≤2		Ref		Ref
≥3		3.0 (1.1 to 8.1)	0.030	3.3 (1.0 to 10.3)	0.044
BMI
BMI<25		Ref		Ref
25≤BMI<30		1.7 (0.6 to 5.0)	0.309	2.3 (0.5 to 9.6)	0.264
BMI≥30		1.2 (0.5 to 3.1)	0.728	1.8 (0.5 to 7.1)	0.411
Sex
Women		Ref		Ref
Men		2.5 (0.9 to 6.6)	0.065	2.8 (0.9 to 8.3)	0.064
Smoking
No		Ref		Ref
Yes		4.9 (0.5 to 51.1)	0.188	5.3 (0.5 to 54.4)	0.160
Diabetes
No		Ref		Ref
Yes		0.6 (0.2 to 2.0)	0.394	1.3 (0.3 to 5.7)	0.774
Rheumatological disease
No		Ref		Ref
Yes		1.2 (0.4 to 3.8)	0.792	1.1 (0.3 to 4.7)	0.883

Numbers in bold mark statistical significance

ASA, American Society of Anesthesiologists; BMI, body mass index.