Supplement 1: Type of procedures, sample size (n), inclusion and exclusion criteria, SSI definitions used and SSI rates in different groups of all included studies
Author
Date
Type of
procedures
n
Inclusion/exclusion criteria
Definition of SSI
Mountain
1970
Appendectomy
150
All patients undergoing emergency
Criteria of Ljungqvist (collection of
appendectomy at a single institution, no pre- pus that emptied itself
specified exclusion criteria
spontaneously or after incision)
Longland
1971
Appendectomy
300
Madsen
1971
Gastric surgery
64
Andersen,
Bendtsen
1972
Appendectomy
490
Andersen,
Korner
1972
Colorectal surgery 240
Logan
1973
Cholecystectomy
100
Mackie
1973
Appendectomy
92
All patients with acute appendicitis
confirmed at operation, no pre-specified
exclusion criteria
All patients undergoing truncal vagotomy
and pyloroplasty. Exclusion: allergy to
penicillin, bad general condition of the
patient
All patients undergoing appendectomy
between June 1969 and Sep 1970. The
study was divided into perforated and nonperforated appendicitis group. No prespecified exclusion criteria.
Patients with established diagnosis of
colorectal cancer from 1st March 1969 to
20th Sept. 1970, undergoing colonic
resections or abdomino-perineal rectum
resections. Exclusion if allergy to penicillin
or ampicillin.
Consecutive patients undergoing
cholecystectomy by the same surgeon were
included. Exclusion criteria: any patient that
required other procedures than the
standardized cholecystectomy were
excluded
Patients undergoing emergency
appendectomy for appendicitis without
perforation or peritonitis. Controls were
patients with penicillin allergy or patients
operated when antibiotic powder was not
available. Exclusion criteria: other surgical
incision techniques or operations performed
by junior staff or consultants, pre- or
postoperative systemic antibiotics, other
surgical procedures necessary, no
histological evidence of appendicitis.
Intervention
group 1
SSI/n (%)
7/76 (9,21%)
Intervention
group 2
SSI/n (%)
x
Control group
SSI/n (%)
Total
SSI/n (%)
18/74 (24,32%)
25/150 (16,67%)
Clinical appearance of sepsis and 9/50 (18,00%)
the isolation of a pathogen from the
discharge
Purulent discharge appearing
0/32 (0,00%)
spontaneously or after surgical
division
1/50 (2,00%)
38/200 (19,00%)
48/300 (16,00%)
x
8/32 (25,00%)
8/64 (12,50%)
Purulent accumulations in the
wound, necessitating surgical
revision.
10/245 (4,08%)
x
42/245 (17,14%)
52/490 (10,61%)
Accumulations of pus occurring
within 30 days after operation and
required surgical revision
3/120 (2,50%)
x
22/120 (18,33%)
25/240 (10,42%)
Wounds were classified in 4
3/52 (5,77%)
categories: 1 slight redness, 2
edema, 3 pus, 4 dehiscence (grade
1 and 2 not considered clinically
significant)
x
1/48 (2,08%)
4/100 (4,00%)
Purulent discharge from the wound
spontaneously or after minor
surgical procedures, criteria of
Ljungqvist
4/31 (12,90%)
2/23 (8,70%)
6/92 (6,52%)
0/38 (0,00%)
Bates
1974
Appendectomy
200
Patients undergoing emergency
appendectomy between august 1971 and
may 1973. Exclusion criteria were: elective
operation, allergy to penicillin, extended or
paramedian incision, use of drains or i.v.
antibiotics or peritoneal lavage
All patients undergoing major urological
surgery. Exclusion criteria: allergy or
sensitivity to the used antibiotics or received
any ototoxic drugs (streptomycin, neomycin,
gentamycin, kanamycin, ethycrinic acid)
within two weeks prior to surgery
All patients undergoing open appendectomy
from 13 jan-9nov 1972, no pre-specified
exclusion criteria
Criteria of Ljungqvist (collection of
pus that emptied itself
spontaneously or after incision)
3/100 (3,00%)
x
16/100 (16,00%)
19/200 (9,50%)
Ciccone
1974
Major abdominal
urological surgery
200
Erythema, induration, purulent
drainage, or complete wound
disruption
3/100 (3,00%)
x
12/100 (12,00%)
15/200 (7,50%)
Gilmore and
Martin
1974
Appendectomy
450
Purulent discharge or positive
culture from a serous discharge
12/149 (8,05%)
14/150 (9,33%)
24/151 (15,89%)
50/450 (11,11%)
Gilmore and
Sanderson
1975
Jensen
1975
Biliary, gastroduodenal,
peritonitis,
intestinal,
appendectomy
miscellaneous
Contaminated
and septic
abdominal
surgery (opening
of hollow viscus)
133
All patients undergoing abdominal surgery,
no pre-specified exclusion criteria.
Purulent discharge or positive
culture from a serous discharge
6/63 (9,52%)
x
18/70 (25,71%)
24/133 (18,05%)
267
All patients undergoing laparotomy with
opening of a hollow viscus before closure of
the main abdominal incision, including
perforations, peritonitis or intra-abdominal
abscesses. Exclusion criteria: operations
with opening of a hollow viscus after closure
of the main abdominal incision (e.g. loop
colostomy). Clean abdominal operations or
operations with less magnitude than
laparotomy (e.g. appendectomy) were
excluded. Allergy to penicillin.
Patients undergoing intra-abdominal surgery
at a single institution. Exclusion criteria:
surgery for hernias, patients with unhealed
wounds or delayed wound closure, bowel
exteriorization through the wound, intraabdominal drains passing through the
wound, sensitivity to iodine, personal
preference or discretion of the surgeon.
Purulent discharge or positive
culture from sero-sanguinous
discharge
4/96 (4,17%)
6/88 (6,82%)
6/83 (7,23%)
16/267 (5,99%)
McCluskey
1976
Biliary, gastroduodenal,
appendectomy,
colonic resection,
miscellaneous
110
According to the criteria of
Ljungqvist, discharge of pus or
copious amount of discharge with
positive culture
21/56 (37,50%)
x
14/54 (25,93%)
35/110 (31,82%)
Galland
1977
Cholecystectomy,
gastrectomy,
gastro-duodenal,
intestinal,
laparotomy,
colorectal,
appendectomy
Urgent abdominal
operations
78
All patients that underwent laparotomy,
including emergency procedures. Exclusion
criteria: pregnancy, renal function or
auditory impairment, antibiotic therapy for
other reasons prior to operation or
postoperatively
Stokes
1977
117
Barr
1978
Partial colectomy,
subtotal
gastrectomy
88
Tanphiphat
1978
Appendectomy
246
Andersen,
Burcharth
1980
Cholecystectomy
(n=113), inguinal
hernia (n=285)
398
Galle
1980
67
Foster
1981
Radical
hysterectomy,
abdominal
hysterectomy or
cervicectomy
Appendectomy
Gray
1981
Biliary, gastroduodenal,
intestinal and
miscellaneous
153
236
Painful wound surrounded by
induration or erythema which
subsided after the release of pus
from the wound
14/39 (35,90%)
x
18/39 (46,15%)
32/78 (41,03%)
All adult patients admitted for urgent
Wound healing classified as
abdominal surgery, no exclusion criteria pre- 1=clinically infected and needing
specified
treatment, 2=mild clinical infection
with discharge not needing any
specific treatment
Not specified, inclusion period 1973-1974,
Not specified
patients undergoing other types of
gastrointestinal surgery were not included in
the final analysis
All patients undergoing emergency
Collection of pus which emptied
appendectomy for acute appendicitis.
itself spontaneously or after
Exclusion criteria: age<15years, allergy to
incision
penicillin, treatment with antibiotics
preoperatively, missing confirmation of
histological appendicitis
All patients undergoing surgery for direct
Wound infection was defined as
inguinal hernia or gallstones without
collection of pus in the wound that
infection of the gallbladder. Exclusion if
required revision. Suture sinus was
allergy to penicillin
defined as discharging sinus that
healed spontaneously after
removal of the suture.
Patients undergoing surgery for
Purulent drainage spontaneously
gynecological malignancies, no further
or after probing
specified criteria
11/55 (20,00%)
x
21/62 (33,87%)
32/117 (27,35%)
1/28 (3,57%)
x
23/60 (38,33%)
24/88 (27,27%)
4/122 (3,28%)
x
12/124 (9,68%)
16/246 (6,50%)
5/196 (2,55%)
x
7/102 (6,86%)
12/398 (3,02%)
9/31 (29,03%)
x
9/36 (25,00%)
18/67 (26,87%)
All patients admitted for emergency
appendectomy at a single institution.
Exclusion criteria: <age of 12 years, patients
who received additional antibiotic therapy
All patients undergoing elective abdominal
surgery under the care of one consultant
during 15months. Exclusion criteria: allergy
to iodine, emergency procedures
Purulent discharge, either
spontaneously or on incision
29/119 (24,37%)
x
27/117 (23,08%)
56/236 (23,73%)
(a) major infection with copious
purulent discharge (b)minor
infection with scanty discharge of
pus
7/71 (9,86%)
x
20/82 (24,39%)
27/153 (17,65%)
Kothuis
1981
Elective
220
laparotomy
(biliary, gastroduodenal,
vascular,
colorectal,
ileocolic)
Colorectal surgery 240
for carcinoma
Ostergaard
1981
Walsh
1981
De Jong
1982
Galland
1983
Appendectomy
200
Lord
1983
Biliary surgery,
gastro-duodenal
surgery,
colorectal surgery
200
Rogers
1983
Hernias,
cholecystectomy,
laparotomy,
biliary, colorectal,
gastro-duodenal,
intestinal,
perforations
187
Appendectomy,
627
gastro-duodenal,
biliary tract,
colonic,
miscellaneous
Colon resection,
582
appendectomy,
gastric- and biliary
surgery, hernia,
various
All patients undergoing elective laparotomy,
no pre-specified exclusion criteria
Wound infection was defined as
formation of a wound abscess,
complicated wound healing was
defined as erythema, seroma,
hematoma or edema
Consecutive series of patients undergoing
colorectal surgery for colorectal carcinoma,
no pre-specified exclusion criteria
All patients undergoing abdominal
procedures at a single institution over a
period of 12 months, no pre-specified
exclusion criteria
All patients undergoing intra-abdominal
operations or operations for inguinal hernia
from 1st april 1980 to 1st feb 1981.
Exclusion criteria: age<5years, vascular
reconstruction within surgery, and therapy
with parenteral antibiotics. 33 patients had
two wounds that were evaluated.
All patients admitted for emergency
appendectomy at a single institution.
Exclusion criteria: <age of 12 years, patients
who received antibiotic therapy within 7
days prior the operation, pregnancy
Patients undergoing elective or emergency
operations of the gastrointestinal tract.
Exclusion criteria: use of parenteral
antibiotics pre- or intra-operatively,
colostomy necessary, or presence of frank
pus at operation.
Patients undergoing general surgery at a
single institution between 1st July and 31
Dec 1979, exclusion criteria: operations of
the anorectal area, patients that died or
needed reoperation within 3 weeks of initial
surgery except their wounds were obviously
infected, vascular and head and neck
surgery was also excluded.
16/102 (15,69%)
x
15/118 (12,71%)
31/220 (14,09%)
Accumulation of pus within 30 days 3/120 (2,50%)
postoperatively, requiring surgical
revision
Purulent discharge or positive
28/308 (9,09%)
culture of serous discharge.
x
22/120 (18,33%)
25/240 (10,42%)
x
40/319 (12,54%)
68/627 (10,85%)
Purulent discharge, or positive
bacteriological culture from wound
discharge
39/303 (12,87%)
x
45/279 (16,13%)
84/582 (14,43%)
Presence of pus in the wound or
purulent discharge from the wound
13/95 (13,68%)
x
14/105 (13,33%)
27/200 (13,50%)
Not specified
3/100 (3,00%)
x
9/100 (9,00%)
12/200 (6,00%)
Any purulent discharge regardless
of culture results
4/86 (4,65%)
x
11/101 (10,89%)
15/187 (8,02%)
Sherlock
1984
Appendectomy
75
All patients with gangrenous or perforated
appendix diagnosed at operation were
included, exclusion criteria: age<18years,
pregnancy, pre-operative administration of
antibiotics.
Sood
1984
Cholecystectomy
or vagotomy with
gastrojejunostomy
55
Juul
1985
Colorectal surgery 203
All patients undergoing clean-contaminated
elective laparotomy in a single institution.
Exclusion criteria: patients with any focus of
infection, metabolic disorders, steroidtherapy.
All patients undergoing elective colorectal
surgery between Apr 1982 and Sept 1983 at
a single institution and gave informed
consent. Exclusion criteria: systemic
antibiotics in the preoperative phase, hypersensitivity of ampicillin or metronidazol.
Lau
1986
Appendectomy
315
All patients undergoing appendectomy
between Sept 1984 and May 1985 who
gave informed consent, no further criteria
pre-specified
Moesgaard
and Nielsen
1988
Abdominoperineal excision
of rectum
79
Moesgaard,
Nielsen and
Hjortrup
1989
Septic abdominal
surgery
(peritonitis at the
time of operation)
177
Raahave
1989
Colorectal surgery 170
Patients undergoing abdomino-perineal
excision of the rectum for cancer or
inflammatory bowel disease between 19821986, pre-specified exclusion criteria
unclear
Patients undergoing abdominal surgery for
peritonitis or intra-abdominal abscess
between Apr 1983 and January 1986 in
three hospitals. Exclusion criteria: hypersensitivity to cephalosporins or
metronidazol, administration of antibiotics
within 4 days prior to operation, pregnancy,
immunologic defects, age <13 years.
Patients scheduled for elective colorectal
surgery that gave informed consent,
exclusion criteria: known allergy to the used
Wound infection was classified as
grade 1=non-infected, grade
2=mild infection (erythema and
serious discharge), 3=severe
infection (purulent discharge or
positive culture from other
discharge requiring secondary
wound healing)
Any purulent discharge from the
wound
6/39 (15,38%)
x
13/36 (36,11%)
19/75 (25,33%)
0/29 (0,00%)
x
4/26 (15,38%)
4/55 (7,27%)
Wound infection was defined as
5/105 (4,76%)
accumulation of pus requiring
surgical drainage; wound
dehiscence was defined as
subcutaneous and fascial
breakdown without accumulation of
pus
Ljungqvist criteria: purulent
9/159 (5,66%)
discharge and wounds with serous
discharge which gave positive
bacteriological cultures, (patients in
which serous discharge was
reported only per phone were
regarded as wound infections.)
Accumulation of pus, draining
24/41 (58,54%)
spontaneously or after opening the
wound
x
5/98 (5,10%)
10/203 (4,93%)
x
3/156 (1,92%)
12/315 (3,81%)
x
22/38 (57,89%)
46/79 (58,23%)
Accumulation of pus, draining
spontaneously or after opening the
wound
15/87 (17,24%)
x
14/90 (15,56%)
29/177 (16,38%)
Collection of pus draining
spontaneously or after incision at
the site
5/81 (6,17%)
x
6/89 (6,74%)
11/170 (6,47%)
antibiotics, antibiotic treatment in the last
three days prior to surgery, patients in which
the colon was not opened, patients that did
not adhere to the protocol.
All patients undergoing emergency
appendectomy and had acute appendicitis
confirmed at histology, exclusion criteria:
known allergies to the used antibiotics,
elective surgery, age <12 years,
preoperative treatment with antibiotics.
Seco
1989
Appendectomy
246
Mathelier
1992
Cesarean section
308
Patients undergoing cesarean section at 3
different hospitals by the same gynecologist.
Exclusion criteria: systemic infections at
randomization that required antibiotic
therapy pre- and postoperatively.
CervantesSanchez
2000
Appendectomy
283
Al-Ramahi
2006
Abdominal
gynecological
procedures
206
All patients with clinical diagnosis of acute
abdomen suggestive of appendicitis
(laboratory and x-ray) confirmed during
operation and by histology, written informed
consent. Exclusion criteria were: age
<5years, allergy to the used antibiotics,
antibiotic therapy 72h before operation,
pregnancy, other intra-peritoneal infections,
any immune deficiency (diabetes, chronic
renal insufficiency, malnourishment,
corticosteroid therapy, asplenism,
radio/chemotherapy)
All patients undergoing abdominal
gynecological procedures (total abdominal
hysterectomy, ovarian cystectomy,
oophorectomy, myomectomy,
salpingectomy, salpingo-ophorectomy, and
other types of abdominal interventions)
between Nov. 1999 and Sept 2001. no prespecified exclusion criteria
Pradhan
2009
Cesarean section
(emergency)
70
Purulent discharge or positive
culture of serous discharge, if no
culture was obtained the wounds
were not classified infected
5/126 (3,97%)
x
15/120 (12,50%)
20/246 (8,13%)
Purulent discharge or extensive
cellulitis around the surgical
incision, endometritis was defined
as fever+ uterine tenderness+
tachycardia+ decreased lochial
flow or foul lochia
Collection of pus or a positive
bacteriologic culture from a wound
discharge
2/154 (1,30%)
x
13/154 (8,44%)
15/308 (4,87%)
11/127 (8,66%)
x
39/156 (25,00%)
50/283 (17,67%)
Wound discontinuation, purulent
discharge, local tenderness,
hotness or redness
11/104 (10,58%)
x
10/102 (9,80%)
21/206 (10,19%)
1/35 (2,86%)
x
6/35 (17,14%)
7/70 (10,00%)
Patients undergoing emergency cesarean
Not specified
section between Apr 2006 and Jan 2008, no
pre-specified exclusion criteria
Güngördük
2012
Cesarean section
520
Patients were eligible if they were >37
weeks gestation and required cesarean
section (elective/emergency) and gave
written informed consent. Exclusion: anemia
<7g/dl Hb, chorio-amnionitis, fever on
admission
Purulent or sero-sanguineous
discharge with induration, warmth
and tenderness. Suspected wound
infections were opened for
confirmation and cultures were
taken.
17/260 (6,54%)
x
19/260 (7,31%)
36/520 (6,92%)