Online appendix 2 Detailed summary of the results (%) for each item and

type of operation.

Hernia repair (HER): 1 Cholecystectomy (CCE): 2

Appendicectomy (APP): 3 Colon surgery (COL): 4

n.a. – not applicable

ITEMS / Answers / HER / CCE / APP / COL
Smoking cessation / Always
Sometimes
Rarely
Never / 10.9
19.6
30.4
37 / 8.5
17
31.9
40.4 / n.a. / 14.9
23.4
21.3
38.3
Nutritional status / Always
Sometimes
Rarely
Never / 8.5
10.6
17
59.6 / 8.5
6.4
25.5
55.3 / n.a. / 36.2
19.1
27.7
14.9
Bowel preparation / Always
Sometimes
Rarely
Never / n.a. / n.a. / n.a. / 15.2
26.1
30.4
26.1
Hair removal / Always
Sometimes
Rarely
Never / 78.7
12.8
0
2.1 / 61.7
14.9
12.8
4.3 / 63.8
19.1
8.5
2.1 / 68.1
19.1
4.3
2.1
Hair removal timing / Day before
Day op / 6.4
89.4 / 8.5
85.1 / 4.3
93.6 / 8.5
87.2
Hair removal instruments / Razor blades
Foam
Clippers / 2.2
4.4
88.9 / 0
4.3
89.1 / 4.3
0
91.3 / 4.3
2.2
89.1
Adhesive drapes / Always
Sometimes
Rarely
Never / 27.7
14.9
12.8
44.7 / 2.1
2.1
4.3
89.4 / 6.4
2.1
4.3
85.1 / 17
14.9
17
48.9
Type adhesive drapes / Antiseptic
Not / 21.3
29.8 / 6.4
27.7 / 6.4
27.7 / 17
36.2
Double gloving / Always
Sometimes
Rarely
Never / 6.4
2.1
38.3
51.1 / 6.4
2.1
36.2
55.3 / 6.4
2.1
38.3
53.2 / 6.4
2.1
42.6
46.8
Routine glove change / >2h
>4h
>6h
Never / 21.3
19.1
0
51.1 / 19.1
19.1
0
40.4 / 21.3
19.1
0
38.3 / 40.4
38.3
4.3
12.8
Gloves change before mesh placement / Yes
No / 66
31.9 / n.a. / n.a. / n.a.
Gloves change depending on contamination / Class II
Class III
Class IV / 46.8
42.6
31.9 / 38.3
46.8
34 / 42.6
59.6
42.6 / 48.9
66
46.8
Routine laparoscopy / Always
Electively
Often
Never / 2.2
8.8
26.5
52.1 / 97.7
2.2
0
0 / 51
4.4
39.9
4.4 / 11
30.9
43.3
13.2
Intracavity lavage / Always
Sometimes
Rarely
Never / 51.1
14.9
21.3
8.5 / 59.6
27.7
8.5
0 / 78.7
17
0
0 / 83
12.8
0
0
Product for intracavity lavage / Saline
Iodine
Antibiotics
Other / 80.9
12.8
0
0 / 89.4
6.4
0
0 / 85.1
10.6
0
2.1 / 83
12.8
0
2.1
Wound irrigation / Always
Sometimes
Rarely
Never / 55.3
19.1
14.9
8.5 / 57.4
23.4
8.5
8.5 / 72.3
19.1
2.1
4.3 / 78.7
12.8
2.1
4.3
Product for wound irrigation / Saline
Iodine
Other / 78.7
10.6
0 / 76.6
12.8
2.1 / 68.1
23.4
2.1 / 68.1
23.4
2.1
Intrabdominal drains / Always
Sometimes
Rarely
Never / n.a. / 0
4.3
68.1
23.4 / 0
6.4
72.3
17 / 21.3
21.3
46.8
6.4
Intrabdominal drains - removal / After 1-2 d
After 3-4 d
After >4 d / n.a. / 46.8
25.5
6.4 / 36.2
36.2
10.6 / 17
27.7
42.6
Subcutaneous drains / Always
Sometimes
Rarely
Never / 2.1
17
21.3
48.9 / 2.1
4.3
17
74.5 / 2.1
6.4
21.3
68.1 / 8.5
10.6
23.4
55.3
Subcutaneous drains - removal / After 1-2 d
After 3-4 d
After >4 d / 42.6
0
0 / 31.9
0
0 / 31.9
0
0 / 29.8
4.3
0
Wound dressing / Occlusive
non / 38.2
57.4 / 36.2
59.6 / 25.5
70.2 / 27.7
68.1
Leave undressed / Day 2-3
Day 4-5
> day 6 / 36.2
36.2
17 / 36.2
36.2
17 / 38.3
36.2
17 / 36.2
34
21.3
Hand disinfection before dressing change / Always
Sometimes
Rarely
Never / 87.2
10.6
0
0 / 87.2
10.6
0
0 / 87.2
10.6
0
0 / 87.2
10.6
0
0
Sterile technique for dressing change / Always
Sometimes
Rarely
Never / 55.3
4.3
19.1
14.9 / 55.3
4.3
19.1
14.9 / 55.3
4.3
19.1
14.9 / 55.3
4.3
19.1
14.9