Table 3 Risk factors for surgical site infection (SSI).

Gender

   Male

4,406

97/1521

1.30 (0.99–1.70)

0.054

1.13 (0.83–1.55)

0.429

   Female

144/2,885

Age, years

   18–36

4,172

35/1,101

1

   37–54

45/1,004

1.43 (0.89–2.30)

0.118

1.11 (0.72–1.69)

0.635

   55–70

67/1,107

1.96 (1.27–3.04)

0.001

0.91 (0.63–1.31)

0.622

   >70

88/960

3.07 (2.02–4.69)

<0.001

1.51 (0.91–2.51)

0.113

Emergency Interventions

   Yes

4,396

69/944

1.50 (1.11–2.03)

0.005

1.73 (1.22–2.44)

0.002

   No

172/3,452

NNIS score

   M

4,330

8/341

1

   0

90/2,507

1.55 (0.72–3.48)

0.237

1.18 (0.77–1.82)

0.441

   1

90/1,182

3.43 (1.59–7.71)

<0.001

1.82 (1.14–2.90)

0.012

   2 + 3

41/300

6.59 (2.91–15.50)

<0.001

3.34 (1.41–7.93)

0.006

Prosthesis

   Yes

4,393

23/762

0.60 (0.39–0.91)

0.011

0.62 (0.38–1.04)

0.07

   No

218/3,631

Pre-operative hospital stay, days

4,337

130/3,136

2.15 (1.63–2.83)

<0.001

1.45 (1.06–1.98)

0.02

   0–1

102/1,201

   >1

Drains

   No

4,406

97/2,894

1

   1–3 days

31/702

3.04 (2.31–3.99)

<0.001

2.39 (0.65–1.65)

<0.001

   >3 days

111/810

4.58 (3.41–6.15)

<0.001

2.17 (1.38–3.43)

<0.001

Perioperative prophylaxis

   Yes

4,406

213/3,857

0.92 (0.60–1.40)

0.684

-

-

   No

28/549