Table S1. Search string.
Search string/terms MEDLINE and EMBASE
("Surgical site infection*" OR "wound infection*" OR "Postoperative wound infection*" OR
"Operation field infection*" OR "Surgical area infection*" ) AND ( "Skin surger*" OR
"Dermatologic surger*" OR "dermatological surger*" OR "Cutaneous surger*" OR
"Dermasurger*" OR "Dermatosurger*") CENTRAL
(“surgical site infection” OR “surgical site infections” OR “wound infection” OR “wound infections” OR “postoperative wound infection” OR “postoperative wound infections” OR
“operation field infection” OR “operation field infections” OR “surgical area infection” OR
“surgical area infections”) AND (“skin surgery” OR “skin surgeries” OR “Dermatologic surgeries” OR “cutaneous surgery” OR “cutaneous surgeries” OR “dermasurgery” OR
“dermasurgeries” OR “dermatosurgery” OR “dermatosurgeries”)
Trial register
controlled-trials.com: “surgical site infection”
ClinicalTrials.gov: "surgical site infection" AND "skin surgery"
anzctr.org.au: "surgical site infection"
who.int/trialsearch: “surgical site infection AND skin surgery OR dermatosurgery”
clinicaltrialsregister.eu: "surgical site infection"
Table S2. Differences between protocol and review.
Differences between protocol and review
In the protocol, we considered I² of 50% as substantial heterogeneity and did not intent to perform meta-analysis. However, there were plausible reasons for clinical and methodological heterogeneity among the studies. Therefore, we decided to pool data and interpret findings in the context of heterogeneity. In addition, we adapted the I² - levels according to the Cochrane handbook: 0-40% as not important, 40-60% as moderate, 60-90% as substantial and 90-100% as considerable.
We only identified observational studies that reported suitable data. There was no controlled clinical trial nor case-controlled trial with adequate data in order to qualify for inclusion. Therefore, risk of bias assessment was limited to the
Newcastle-Ottawa scale. Evaluation of the quality of the evidence using the GRADE approach was not feasible.
Two authors are mentioned in the protocol that supported the project during the early stages (Matthias Deichsel, Markus Reinholz). However, their overall
contribution did not qualify for authorship. In contrast, two other authors joined
our team after the protocol was published. They contributed significantly and are
therefore listed as authors (Virginia Ruiz San Jose, Kathrin Patzer).
Table S3. Reasons for Exclusion of other studies.
Excluded studies
Study Reason for exclusion
Evaluating complications in below-knee skin cancer surgery after introduction of preoperative appointments: A 2-year retrospective cohort study – Lindholm et al. 2020
Study objective was not in line with review question.
No suitable data reported.
Infection rates post-Mohs micrographic surgery in a tertiary referral centre – Victor et al. 2018
This was a conference abstract.
Postoperative risk factors of organ transplant recipients following dermatosurgical procedures – Kropfl et al. 2016
This was a poster abstract. No relevant data reported.
Adverse outcomes after major surgery in patients with pressure ulcer: A nationwide population-based retrospective cohort study - Chou et al. 2015
Study objective not in line with review question.
Cutaneous Surgery Complications in Individuals Aged 80 and Older Versus Younger Than 80 After Excision of Nonmelanoma Skin Cancer – Pascual et al.
2015
Analyzed study population did not meet predefined age-range of interest (>60 vs <60 years). No other relevant data reported.
Infection rates after minor dermatosurgery at neath port talbot hospital-a snap shot – Taylor et al. 2020
This was a poster abstract.
Office based dermatological surgery and Mohs surgery: A prospective audit of surgical procedures and complications in a procedural dermatology practice – Elliott et al. 2012
No relevant data reported.
Wound infection rates in elective plastic surgery for HIV-positive patients – Reilly et al. 2009
All patients received perioperative antibiotic prophylaxis.
Perioperative management and the associated rate of adverse events in dermatological procedures performed by dermatologists in New Zealand – Chan et al. 2009
This was a survey including a questionnaire for dermatologists. The study design was not suitable for inclusion.
Infections after dermatologic surgery - Korstanje et al. 2006 The fulltext was not available.
Reducing infections in cutaneous oncology defects reconstructed using skin grafts – Tahir et al. 2005
No suitable data reported.
A prospective evaluation of the incidence of complications associated with Mohs micrographic surgery – Cook et al. 2003
No suitable data reported.
Risk factors related to surgical site infection in dermatological surgery. A prospective study in a third level hospital. - Juarez Dobjanschi et al 2021
The fulltext was not available.
Risk Factors for Surgical Site Infection after Minor Dermatologic Surgery. – Delpachitra et al. 2021
Data from other studies summarized, including randomized controlled trials that examined interventions with potential impact on SSI occurrence.
Factors associated with surgical site infection of the lower extremity: A retrospective cohort study. – Nathan et al. 2020
No suitable data reported in order to compare different anatomic locations.
A prospective study to evaluate the safety of minor cutaneous surgery during aspirin treatment
Schein et al. 2010
Article published in Hebrew. No German or English translation available.
A prospective randomised comparison of minor surgery in primary and secondary care. The MiSTIC trial – George et al. 2008
The fulltext was not available.
Surgical Site Infections in Plastic Surgery: An Italian Multicenter Study – Drapeau et al. 2007
Study assessed interventions beyond the scope of dermatologic surgery. No data for superficial skin surgery separately reported.
Surgical Site Infection After Skin Excisions in Children: Is Field Sterility Sufficient? – Nuzzi et al. 2016
Only simple excisions in pediatric population assessed. No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Risk factors for wound infection after minor surgery in general practice – Heal et al. 2006
Only simple excisions in primary care analyzed. No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Prospective evaluation of dermatologic surgery complications including patients on multiple antiplatelet and anticoagulant medications – Bordeaux et al. 2011
No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Sterile Versus Nonsterile Gloves During Mohs Micrographic Surgery: Infection Rate is not Affected - Rhinehart et al. 2006
No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Infection control practices and infectious complications in dermatological surgery - Rogues et al. 2006
No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Postoperative infection following clean facial surgery – Sylaidis et al. 1997 No suitable data on surgery-related risk factors or preoperative skin contamination reported.
A 4-year Retrospective Assessment of Postoperative Complications in Immunosuppressed Patients Following – Basu et a. 2018
No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Surveillance of nosocomial infections in dermatology patients in a German university hospital - Dettenkofer et al. 2003
No suitable data on surgery-related risk factors or preoperative skin contamination reported.
Incidence and Predictors of Lower Limb Split-Skin Graft Failure and Primary Closure Dehiscence in Day-Case Surgical Patients - Stankiewicz et al. 2015
Review question was not addressed.
Wound Complications Following Diagnostic Skin Biopsies in Dermatology Inpatients – Wahie et al. 2007
No relevant data for wound infection separately reported.
Nasal Carriage of Staphylococcus Aureus in Patients Undergoing Mohs Micrographic Surgery Is an Important Risk Factor for Postoperative Surgical Site Infection: A Prospective Randomised Study - Tai et al. 2013
Conflicting data between table and text: in text data per intervention, in table data per patient reported.
Relevant statistical information not computable, including the incidence.
Clinical Characteristics of Lower Extremity Surgical Site Infections in Dermatologic Surgery Based Upon 24-Month Retrospective Review - Bari et al. 2018
The fulltext was not available.
Comparing Demographic Characteristics and Adverse Event Rates at Two Dermatologic Surgery Practices - O'Neill et al. 2014
No adequate data for analysis reported.
Adverse Events Associated With Mohs Micrographic Surgery: Multicenter Prospective Cohort Study of 20,821 Cases at 23 Centers – Alam et al. 2013
No adequate data for analysis reported.
Cutaneous Surgery Under Local Anesthesia in Very Elderly Patients 90 Years of Age and Older Is as Safe as in Elderly Patients Ranging in Age From 75 to 80 Years Old – Imamura et al. 2017
Study population did not meet predefined age-range of interest (>60 vs <60 years). No other relevant data reported.
Risk Factors in Pediatric Dermatologic Surgery – Roldan et al. 2009 No relevant data reported.
Lack of Complications in Skin Surgery of Patients Receiving Clopidogrel as Compared With Patients Taking Aspirin, Warfarin, and Controls - Kramer et al.
2010
No data for incidence of surgical site infection (SSI) reported separately (only together with wound- dehiscence).
Wound Infection Rate in Dermatologic Surgery - Whitaker et al. 1988 No relevant data reported.
Postoperative complications in dermatological patients undergoing microscopically controlled surgery in inpatient setting (next-day surgery): A single-center epidemiological study. – Artamonova et al. 2021
No suitable data for analysis reported (only p-values or odds ratios without confidence interval).
Observations Regarding Infection Risk in Lower-Extremity Wound Healing by Second Intention. - Molina et al. 2020
First follow-up was too long in order to detect SSI (2 months).
Outpatient dermatology major surgery: a 1-year experience in a Spanish tertiary hospital. - Fernández-Jorge et al. 2006
No suitable data for analysis reported.
Infection rates of wound repairs during Mohs micrographic surgery using sterile versus nonsterile gloves: a prospective randomized pilot study – Xia et al. 2011
Study design and study objective not in line with review question.
A prospective study of infection rate in second intention wounds - Verykiou et al. 2019
No feasible data for analysis reported. No information given if "presumed infection diagnosed in primary or emergency care" occurred during postoperative timeframe (14d).
Head and neck free flap surgical site infections in the era of the Surgical Care Improvement Project - Yarlagadda et al. 2016
Surgical procedures were beyond the field of dermatosurgery.
Complications in dermatological surgery: A singlecentre experience – Khoo et al. 2016
This was a conference abstract.
A prospective randomised study of Staphylococcus aureus nasal carriage as a major risk factor for infection in Mohs micrographic surgery – Tai et al. 2012
The fulltext not available.
Incidence and risk factors of postoperative wound infections after dermatological surgery -
De Vries et al. 2010
The fulltext not available.
Table S4. Characteristics of the included studies – PAP – perioperative antibiotic prophylaxis, PSOS – prospective single- center observational study, PMOS – prospective multi-center observational study, RSCS – retrospective single-center cohort study, RMCS – retrospective multi-center cohort study, GP – general practitioner, MMS – Moh’s micrographic surgery
*this was the mean age of the study cohort, which also included patients that received interventions beyond the scope of dermatologic surgery. **computed, mean age reported for patients with and without surgical complications separately.
Characteristics of the included studies
Nr. Study Medical discipline
Study desig n
Incidenc e of SSI (%)
N = patients/
interventions
Age PAP
included
Setting of surgery
Type of surgical procedures
Additional information
Study qualit y
1 Liu et al. Dermatolog PSOS 4.00 1977 66.2 no out- and Dermatosurgical Minor good
2017 y interventions inpatients procedures in local anesthesia
interventions (e.g.
biopsies) excluded 2 Futoryan et
al. 1995
Dermatolog y
RSCS 2,29 1047
interventions not reported
yes outpatient
s
Dermatosurgical procedures
All wounds were closed within the same day.
good
3 Heal et al.
2012
General Medicine
PMOS 8.70 972 patients 59.3 no ambulator
y care
Minor excisions (two-layer) including skin flaps
Surgery performed by GP
good
4 Kulichová et al. 2013
Dermatolog y
PSOS 1.90 3284
interventions not reported
yes inpatients Dermatosurgical procedures
poor 5 Amici et al.
2005
Dermatolog y
PMOS 2.00 3788
patients
51.5 yes out- and
inpatients
Dermatosurgical procedures
Infected sebaceous cysts and pyoderma excluded.
poor
6 Dixon et al.
2006
Dermatolog y
PSOS 1.47 5091
interventions
57.5 not
reported
inpatients Dermatosurgical procedures
Skin graft donor sites were not included for analysis.
good
7 Balakirski et al. 2020
Dermatolog y
RMCS 6.70 134
interventions
74 yes, but
not as SSI- prophylaxis
inpatients MMS Only
immunosuppresse d patients analyzed
fair
8 Balakirski et al. 2018
Dermatolog y
RSCS 6.70 284
interventions
77 no inpatients Dermatosurgical
procedures
Minor
interventions (e.g.
simple excisions) excluded.
fair
9 Penington 2008
Surgery PSOS 7.25 924
interventions
64.5 not
reported
outpatient s
Procedures in local anesthesia
Biopsies excluded. poor 10 Nakamura
et al. 2021
Dermatolog y
RSCS 5.50 512 patients 60 yes outpatient
s
Procedures in local anesthesia
Surgery of subcutaneous tumors (e.g.
lipoma) excluded
poor
11 Schmitt et al. 2018
Dermatolog y
RSCS 5.00 331
interventions
74 yes outpatient
s
Only complex repairs analyzed
good
12 Toia et al.
2011
Plastic surgery
PSOS 0.96 517
interventions
58.1* no inpatients Skin surgery
and mucosal excisions
Only data of “group 1” which underwent skin surgery considered for this review
good
13 Maragh et al. 2008
Dermatolog y
PSOS 0.70 1115
interventions not reported
no outpatient
s
MMS with complex repair
good 14 Schliephake
et al. 1994
Maxillo- Facial Surgery
RSCS 5.12 273 patients 63,2 yes inpatients Skin tumor
surgery under general anesthesia
Surgery was limited on the head and neck area
poor
15 Schimmel et al. 2020
Dermatolog y
RSCS 3.90 5679
interventions not reported
No inpatients Skin cancer
surgery with dermatosurgical reconstruction
Partial closures, delayed repairs, interpolated flaps, and purse string closures not included for analysis.
poor
Table S5. Quality assessment of the included studies according to the Newcastle-Ottawa Scale (NOS) (12)
Study quality assessment - Newcastle-Ottawa Scale (NOS)
Study Selection Comparability Outcome Total Nr. of stars Quality
Liu et al. 2017 **** ** *** 9 good
Heal et al. 2012 **** ** *** 9 good
Kulichová et al. 2013 *** ** * 6 poor
Amici et al. 2005 **** ** * 7 poor
Dixon et al. 2006 **** * *** 8 good
Schimmel et al. 2020 ** * * 4 poor
Balakirski et al. 2020 ** ** *** 7 fair
Balakirski et al. 2018 ** * *** 6 fair
Penington et al. 2008 *** * * 5 poor
Nakamura et al. 2021 *** ** * 6 poor
Schmitt et al. 2018 *** * *** 7 good
Maragh et al. 2008 *** * ** 6 good
Schliephake et al. 1994 *** * 4 poor
Toia et al. 2011 **** ** *** 9 good
Futoryan et al. 1995 *** * *** 7 good
Figure S1. PRISMA-Studyflow diagram.
Adapted and modified from: Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. Doi: 10.1136/bmj.n71
Identification of studies via databases and registers
Records removed before screening:
Duplicate records removed (n = 28)
Records marked as ineligible by automation tools (n = 0) Records removed for other reasons (n = 0)
Records identified from:
Pubmed/Medline (n = 316) Embase (n = 332)
Cochrane Library (n = 64) Studyregister (n = 179) Identification
Records excluded (n = 808)
Records screened (n = 863)
Fulltext sought for retrieval
(n = 55) Fulltext not retrieved
(n = 8) Screening
Reports excluded (n = 28):
Inadequate study design (n = 1) No suitable data reported (n = 18) Study question not addressed (n = 4) Other reasons (n = 5)
Fulltext assessed for eligibility (n = 47)
Figure S2. Forest plot for the risk factor simple wound closure.
Figure S3. Funnel plot for the risk factor local flaps. There was no sign of publication bias (intercept = 0.207; t = 0.189; p = 0.855).
Studies reporting relevant data on risk factors for SSI (n = 19) Relevant studies identified from reference lists (n = 4)
Studies not reporting data on procedure-related factors (n = 8)
Included
Included studies (n = 15)
