Table 1.

Descriptive statistics of the overall sample cum patients with and without SSI.

	Total sample (N = 446)	Matched groups
		SSI (n = 40)	Non-SSI (n = 40)
Sex
Male	171 [38.0]	9 [22.5]	9 [22.5]
Female	275 [62.0]	31 [77.5]	31 [77.5]
	446 [100.0]	40 [100.0]	40 [100.0]
Wound Class
Clean	289 [64.7]	10 [25.0]	10 [25.0]
Clean contaminated	30 [6.7]	3 [7.5]	3 [7.5]
Contaminated	57 [12.7]	9 [22.5]	9 [22.5]
Dirty	70 [15.9]	18 [45.0]	18 [45.0]
Total	446 [100.0]	40 [100.0]	40 [100.0]
Procedure
Colon surgery	16 [3.6]	5 [12.5]	5 [12.5]
Herniorrhaphy	88 [19.7]	11 [27.5]	11 [27.5]
Thyroid surgery	40 [9.0]	3 [7.5]	3 [7.5]
Appendix surgery	69 [15.5]	6 [15.0]	6 [15.0]
Breast surgery	64 [14.3]	7 [17.5]	7 [17.5]
Rectal surgery	8 [1.8]	1 [2.5]	1 [2.5]
Small bowel surgery	8 [1.8]	2 [5.0]	2 [5.0]
Gall bladder surgery	5 [1.1]	2 [5.0]	2 [5.0]
Limb amputation	98 [22.0]	2 [5.0]	2 [5.0]
Bile duct, liver	3 [0.7]	–	–
Laparotomy	47 [10.5]	1 [2.5]	1 [2.5]
Total	446 [100.0]	40 [100.0]	40 [100.0]
Mean age (years)	46 [6–98]	41 [14–78]a	40 [16–76]

^aMinimum and maximum ages in parenthesis.