Early versus delayed dressing removal after primary closure of clean and clean‐contaminated surgical wounds (2024)

Monitoring Editor: Clare D Toon, Charnelle Lusuku, Rajarajan Ramamoorthy, Brian R Davidson, Kurinchi Selvan Gurusamy, and Cochrane Wounds Group

West Sussex County Council, Public Health Research Unit, The Grange, County Hall Campus, Tower Street, ChichesterWest SussexUK, PO19 1QT

The University of Nottingham, School of Medicine, NottinghamUK, NG7 2UH

Royal Free Campus, UCL Medical School, Department of Surgery, Royal Free Hospital, Pond Street, LondonUK, NW3 2QG

Early versus delayed dressing removal for people with surgical wounds

Most surgical procedures involve a cut in the skin that allows the surgeon to gain access to the deeper tissues or organs. Most surgical wounds are closed fully at the end of the procedure.The surgeon covers the closed surgical wound with either a dressing or adhesive tape.The dressing can act as a physical barrier to protect the wound until the continuity of the skin in restored (within about 48 hours). It can also absorb exudate from the wound, keeping it dry and clean, and preventing bacterial contamination from the external environment. Some studies have found that the moist environment created by some dressings accelerates wound healing, although others believe that it is a disadvantage, as excessive exudate can cause softening and deterioration of the wound and surrounding healthy tissue.

We reviewed the medical literature up to July 2013 and identified four randomised controlled trials that investigated early (permanent removal of dressings within 48 hours of surgery) versus delayed removal of dressings (permanent removal of dressings after 48 hours of surgery with interim changes of dressing allowed) in people with surgical wounds. The levels of bias across the studies were mostly high or unclear, i.e. flaws in the conduct of these trials could have resulted in the production of incorrect results. A total of 280 people undergoing planned surgery were included in this review. One‐hundred and forty people had their dressings removed within 48 hours following surgery and 140 people had their wounds dressed beyond 48 hours. The choice of whether the dressing was removed early (within 48 hours) or retained for more 48 hours was made randomly by a method similar to the toss of a coin. No significant differences were reported between the two groups in terms of superficial surgical site infection (infection of the wound), superficial wound dehiscence (partial disruption of the wound that results in it reopening at the skin surface) or the number of people experiencing serious adverse events. There were no deep wound infections or complete wound dehiscence (complete disruption of wound healing, when the wound reopens completely) in the studies that reported these complications. However, the studies were not large enough to identify small differences in complication rates. None of the studies reported quality of life. Participants in the group that had early removal of dressings had significantly shorter hospital stays and incurred significantly lower treatment costs than those in the delayed removal of dressings group, but these results were based on very low quality evidence from one small randomised controlled trial. We recommend further randomised controlled trials are performed to investigate whether dressing of wounds beyond 48 hours after surgery is necessary, since the current evidence is based on very low quality evidence from three small randomised controlled trials.

Description of the condition

Most surgical procedures involve a cut in the skin that allows the surgeon to gain access to the deeper tissues or organs. Most surgical wounds are closed fully at the end of the procedure.This is called primary closure (Garcia‐Gubern 2010). The various techniques for wound closure include closure using sutures, staples, adhesive tapes and tissue glue (Ahn 2011; Biancari 2010; Hasan 2009). Primary closure is essential to restore the skin barrier, which prevents infection of deeper tissues. However, it is not always possible to maintain clean conditions throughout surgery, for example, when operating on a contaminated wound (external wounds resulting from trauma) or when operating on tissues that contain contaminated material (e.g. surgery on the colon, which contains faecal material). In these situations it is sometimes best to delay closure of the wound until the wound develops good granulation tissue, and this is called secondary closure (Garcia‐Gubern 2010).

Various factors affect wound healing, such as infection or mechanical strain leading to wound dehiscence (breakdown of wound along the incision), wound infection (currently termed 'surgical site infection') or both. Three types of surgical site infections (SSIs) have been classified: they are defined as 1) superficial incisional surgical site infections that involve only the skin or subcutaneous tissue around the incision, 2) deep incisional surgical site infections that involve deep soft tissues, such as the fascia and muscles (both occurring within 30 days of procedure, or one year in the case of implants), and 3) organ/space surgical site infections that involve any part of the body (excluding the skin incision, fascia or muscle layers) that is opened or manipulated during the operative procedure (Horan 1992). The incidence of SSI varies according to the classification of surgical wounds. Surgical wounds can be classified in different ways. One accepted classification that has been adopted by the Centers for Disease Prevention and Control (CDC) is to define wounds as clean, clean‐contaminated, contaminated, and dirty or infected (Garner 1986). This classification is shown in Appendix 1. The incidence of SSI can vary between 1% and 80% depending upon the types of surgery, the hospital setting (community hospital, tertiary‐care hospital, etc), the classification of surgical wounds, and the method of skin closure (Biancari 2010; Broex 2009; Garner 1986). It is estimated that the presence of SSI can double the costs of surgery (Broex 2009). Some of the methods used to prevent SSI include administration of prophylactic antibiotics and dressing of wounds.

Description of the intervention

Surgeons cover closed surgical wounds using either a dressing or adhesive tape (steri‐strips), or both. Wound dressings are classified in a number of ways according to their function (e.g. occlusive, absorbent), type of material (e.g. hydrocolloid, collagen) and the physical form of the dressing (e.g. ointment, film, foam) (Boateng 2008). Some dressings are designed to control the environment for wound healing, for example, to donate fluid (hydrogels), maintain hydration (hydrocolloids), or to absorb wound exudates (alginates, foams) (BNF 2011). These dressings can be either transparent (e.g. vapour‐permeable films), so that the wound can be monitored without the need for frequent dressing changes, or non‐transparent. Wound dressings are customarily left in place for at least 48 hours after surgery (delayed dressing removal) irrespective of the level of contamination of wounds, or other factors such as antibiotic administration.

How the intervention might work

Dressings can act as a physical barrier to protect wounds until the continuity of the skin (epithelialisation) has been achieved ‐ this occurs within about 48 hours of surgery (Lawrence 1998) ‐ and to absorb exudate from the wound, keeping it dry and clean with the aim of avoiding bacterial contamination from the external environment (Hutchinson 1991; Mertz 1985; Ubbink 2008). Another reason for using a dressing is to prevent contamination of the surrounding area by any wound discharge (Downie 2010), although this is mainly applicable for clean‐contaminated, contaminated, and dirty or infected wounds. Some studies have found that the moist environment created by some dressings accelerates wound healing (Dyson 1988), although others believe that it is a disadvantage, as excessive exudate can cause maceration (softening and breakdown) of the wound and the surrounding healthy tissue (Cutting 2002). Ideally surgeons choose suitable dressings to ensure that the wound remains:

• free of clinical infection and excessive slough;

• free of toxic chemicals, particles or fibres;

• at the optimum temperature for healing;

• undisturbed by the need for frequent changes;

• at the optimum pH value.

As wound healing progresses, it may be appropriate to use different types of dressings (BNF 2011).

Why it is important to do this review

Dressings applied to surgical wounds at the time of surgery can either be removed early, changed regularly, or retained until the removal of sutures or strips. This may cause inconvenience to the patient and increase nursing time, with an inevitable increase in associated costs (Chrintz 1989; Dosseh 2008; Merei 2004). In simulated wounds, where dressings increase the chance of localised sweating and can reduce moisture evaporation, the resulting increased dampness potentially acts as a nidus (point at which micro‐organisms enter the body) for infection (Gwosdow 1993). Thus, there are some potential disadvantages to delaying dressing removal. There has been no systematic review of early dressing removal (permanent dressing removal within 48 hours after surgery) versus delayed dressing removal (permanent dressing removal 48 hours after surgery with dressing changes allowed in the interim) for surgical wounds.

Criteria for considering studies for this review

Search methods for identification of studies

Data collection and analysis

We performed the systematic review following instructions in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011a).

Description of studies

Risk of bias in included studies

All the trials were at high risk of bias. The proportion of trials with different classifications of risk of bias is shown in Figure 2, and the classification of domains in individual trials is shown in Figure 3.

Effects of interventions

See: Table 1

The results from the meta‐analysis are outlined in the Data and analyses and Table 1. Only seven outcomes were reported in the included trials.

Summary of main results

This review compared the effects of early versus delayed dressing removal on a variety of outcomes, including surgical site infections (SSI), length of hospital stay and overall costs. While four trials were identified for inclusion in this review (Ajao 1977; Dosseh 2008; Ramkumar 2006; Wipke‐Tevis 1998), only three trials contributed to the meta‐analysis (Ajao 1977; Dosseh 2008; Ramkumar 2006). These trials included people undergoing assorted surgical procedures (Ajao 1977); abdominal, cervical or thoracic surgery (Dosseh 2008); unilateral or bilateral primary correction of prominent ears (Ramkumar 2006); and coronary artery bypass graft surgery with saphenous vein grafts (Wipke‐Tevis 1998). The people in the early dressing removal group removed their dressing up to 48 hours after surgery. Those in the delayed dressing removal group continued dressing the wound beyond 48 hours. It was possible to extract data for the following outcomes: both superficial and deep SSI, both superficial and deep wound dehiscence, number of people with adverse events, length of hospital stay, and total costs. None of the trials reported quality of life or time to return to work. There were no significant differences between the groups in terms of incidence of SSIs, wound dehiscence or serious adverse events. The length of hospital stay was two days shorter and the costs were EUR 36 cheaper in the early dressing removal group than the delayed dressing removal group in the only trial that reported this outcome (Dosseh 2008). This trial included direct costs, which included the intervention and the hospitalisation in Togo. Hospital stay is likely to cost more in Western countries. For example, one additional day in hospital costs approximately GBP 250 in the United Kingdom (NHS reference costs 2012).

In the absence of evidence of a difference in complications between the two groups, the shorter hospital stay and the lower costs are likely to be due to the dressing rather than a difference in complications. However one cannot rule out differences in complications, since the trials were not powered to measure these differences. Even if patients are discharged home with further instructions for dressings with the general practitioner (GP) or GP‐nurse or a nurse who visits the home, this will involve costs. If the hospital stay is likely to be longer than 48 hours for surgical reasons (rather than for dressing the wound), dressing the wound involves time for the ward staff. So, irrespective of the setting, dressing beyond 48 hours involves resources other than the cost of the dressings. If this is not balanced by a decrease in the complications, there appears to be no evidence to support dressing surgical wounds beyond 48 hours.

Overall completeness and applicability of evidence

None of the studies reported health‐related quality of life. It is important to measure the quality of life in future trials.

The findings of this review can only be applied to people with clean or clean‐contaminated surgical wounds closed by primary intention. It is not clear whether or not these findings can be applied to people with accidental injuries, or for those people undergoing delayed primary closure.

Quality of the evidence

The overall quality of the evidence is low or very low as shown in Table 1. Most of the results are based on one or two trials. However, it must be pointed out that this is the best available evidence on this topic. Evidence from observational studies may be even more unreliable, since the participants in whom wound complications are not expected to develop because of various factors including co‐morbidities, type of living environment, their ability to keep the wound clean, and the type of surgery performed, may influence the decision to remove the dressing early or late. Such selection bias can result in biased effect estimate.

Potential biases in the review process

Although we performed a thorough review of published literature and current trials, it is possible that some authors have conducted relevant trials in the pre‐registration era and have not reported the results. There are various potential sources of heterogeneity including types of dressing, surgery, and wound closure; degree of contamination; and duration of antibiotic treatment, as mentioned in the 'Subgroup analysis and investigation of heterogeneity' section. However, heterogeneity could not be explored because of the low number of trials included in this review, so the impact of these factors on the effect estimate could not be explored.

Agreements and disagreements with other studies or reviews

This is the first review on this topic. Overall, the trials concluded that wounds can be uncovered within the first 48 hours following surgery with no ill effect. It was also concluded that when dressings were removed within the first 48 hours, people spent significantly less time in hospital and the overall cost of their treatment was significantly reduced compared to people whose wounds were covered beyond the first 48 hours following surgery. While the authors of the individual trials interpreted this to mean that there was no need for dressing beyond the first 48 hours following surgery, we interpret this information with a little more caution and conclude that there is currently no evidence for dressings beyond the first 48 hours and that dressing need not be used for more than 48 hours following surgery involving clean and clean, contaminated wounds until further research shows otherwise.

Implications for practice

The early removal of the dressing from a clean or clean‐contaminated surgical wound appears to have no detrimental effect on the patient. However, it must be noted that the point estimate that supports this conclusion is based on very low quality evidence from three small randomised controlled trials, and that the confidence intervals around this estimate were wide. Furthermore, early dressing removal may result in a significantly shorter hospital stay and significantly reduced costs than covering the surgical wound with a wound dressing beyond the first 48 hours after surgery based on very low quality evidence from one small randomised controlled trial.

Implications for research

Further randomised controlled trials of low risk of bias are necessary to investigate whether dressings are necessary after 48 hours in different types of surgery and levels of contamination and investigate whether antibiotic therapy influences the outcome

This project was funded by the National Institute for Health Research.
Disclaimer of the Department of Health: 'The views and opinions expressed in the review are those of the authors and do not necessarily reflect those of the National Institute for Health Research (NIHR), National Health Services (NHS), or the Department of Health.'

We acknowledge the help and support of the Cochrane Wounds Group. The authors would also like to thank the following editors and peer referees who provided comments to improve the protocol: Susan O'Meara (editor), Evangelos Kontopantelis and Iain McCallum and to Jenny Bellorini for copy editing the protocol. The authors would also like to thank the following editors and peer referees who provided comments to improve the review: Susan O'Meara (editor), Nerys Woolacott, Evan Kontopantelis and AG Radhika and to Elizabeth Royle for copy editing the review.

Comparison 1

Characteristics of included studies [ordered by study ID]

Characteristics of excluded studies [ordered by study ID]

Protocol

Rajarajan Ramamoorthy developed the protocol, completed the first draft of the protocol, performed part of the writing or editing, made an intellectual contribution, and approved the final version prior to submission.¬
Brian Davidson conceived the review question, secured funding, made an intellectual contribution, advised on the protocol, and approved the final version prior to submission.¬
Kurinchi Gurusamy conceived the review question, developed the protocol, co‐ordinated protocol development, secured funding, performed part of the writing or editing of the protocol, made an intellectual contribution, advised on the protocol, and approved the final version prior to submission.

Review

Clare Toon developed the review, completed the first draft, performed part of the writing or editing of the review, made an intellectual contribution and approved the final version prior to submission.
Rajarajan Ramamoorthy made an intellectual contribution and approved the final version prior to submission.¬
Brian Davidson conceived the review question, secured funding, made an intellectual contribution, advised on the review and approved the final version prior to submission.¬
Kurinchi Gurusamy developed the review, co‐ordinated review development, secured funding, performed part of the writing or editing of the review, made an intellectual contribution, advised on the review, approved the final version prior to submission, and is guarantor of the review.

Update

Kurinchi Gurusamy screened the search results, assessed full text articles, edited and approved the final updated review version prior to submission, and is guarantor of the review.
Charnelle Lusuku screened the search results, retrieved articles for assessment and edited the updated review.

Contributions of editorial base

Nicky Cullum: edited the protocol; advised on methodology, interpretation and protocol content. Approved the final protocol prior to submission.
Joan Webster, Editor: approved the final review prior to submission.
Sally Bell‐Syer: co‐ordinated the editorial process. Advised on methodology, interpretation and content. Edited the protocol,review and updated review.
Ruth Foxlee: designed the search strategy and edited the search methods section.
Rachel Richardson: edited the review.

Internal sources

• No sources of support supplied

External sources

• National Institute for Health Research (NIHR ‐ UK Government organisation for health research), UK.

  NIHR provides financial support for K Gurusamy for completing the review

• NIHR / Department of Health (England), (Cochrane Wounds Group), UK.

Ajao 1977 {published data only}

• Ajao OG. Surgical wound infection: a comparison between dressed and undressed wounds. Journal of Tropical Medicine and Hygiene 1977;80(9):192‐6. [PubMed] [Google Scholar]

Dosseh 2008 {published data only}

• Dosseh Ekoue D, Doleaglenou A, Fortey YK, Ayite AE. Randomized trial comparing dressing to no dressing of surgical wounds in a tropical setting [Pansem*nt versus absence de pansem*nt au dela de 48 heures en milieu tropical: essai randomise]. Journal de Chirurgie 2008;145(2):143‐6. [PubMed] [Google Scholar]

Ramkumar 2006 {published data only}

• Ramkumar S, Narayanan V, Laing JHE. Twenty‐four hours or 10 days? A prospective randomised controlled trial in children comparing head bandages following pinnaplasty. Journal of Plastic, Reconstructive and Aesthetic Surgery 2006;59(9):969‐74. [PubMed] [Google Scholar]

Wipke‐Tevis 1998 {published data only}

• Wipke‐Tevis DD, Stotts NA. Effect of dressings on saphenous vein harvest incision pain, distress and cosmetic result. Progress in Cardiovascular Nursing 1998;13(3):3‐13. [PubMed] [Google Scholar]

Chrintz 1989 {published data only}

• Chrintz H, Vibits H, Cordtz TO, Harreby JS, Waaddegaard P, Larsen SO. Need for surgical wound dressing. British Journal of Surgery 1989; Vol. 76, issue 2:204‐5. [PubMed]
• Chrintz H, Vibits H, Harreby JS, Cordtz TO, Waaddegaard P, Larsen SO. Discontinuing postoperative wound dressings. Ugeskrift for Laeger 1989;151(41):2667‐8. [PubMed] [Google Scholar]

Edwards 1967 {published data only}

• Edwards RH, Killen DA. Comparison of two methods of management of clean surgical wounds. "Open" vs "closed" postoperative wound care. JAMA 1967;201(1):137‐8. [PubMed] [Google Scholar]

Law 1987 {published data only}

• Law NW, Ellis H. Exposure of the wound‐‐a safe economy in the NHS. Postgraduate Medical Journal 1987;63(735):27‐8. [PMC free article] [PubMed] [Google Scholar]

Lisy 2014 {published data only}

• Lisy K. Early vs. Delayed Removal of Dressings Covering Surgical Wounds. American Journal of Nursing 2014;23(6):326‐30. [PubMed] [Google Scholar]

Meylan 2001 {published data only}

• Meylan G, Tschantz P. Surgical wounds with or without dressing. Prospective comparative study. Annales de Chirurgie 2001;126(5):459‐62. [PubMed] [Google Scholar]

Springer 2013 {published data only}

• Springer BD, Beaver WB, Griffin WL. The role of surgical dressings in total knee arthroplasty: A randomized clinical trial. Clinical Orthopedic Related Research 2013;24(4):452‐3. [Google Scholar]

Ahn 2011

• Ahn HB, Shin DM, Roh MS, Jeung WJ, Park WC, Rho SH. A comparison of 2‐octyl cyanoacrylate adhesives versus conventional suture materials for eyelid wound closure in rabbits. Korean Journal of Ophthalmology 2011;25(2):121‐7. [PMC free article] [PubMed] [Google Scholar]

Biancari 2010

• Biancari F, Tiozzo V. Staples versus sutures for closing leg wounds after vein graft harvesting for coronary artery bypass surgery. Cochrane Database of Systematic Reviews 2010, Issue 5. [DOI: 10.1002/14651858.CD008057.pub2] [PubMed] [CrossRef] [Google Scholar]

BNF 2011

• British Medical Association and the Royal Pharmaceutical Society of Great Britain. British National Formulary. 1st Edition. BMJ Publishing Group, 2011. [Google Scholar]

Boateng 2008

• Boateng JS, Matthews KH, Stevens HN, Eccleston GM. Wound healing dressings and drug delivery systems: a review. Journal of Pharmaceutical Sciences 2008;97(8):2892‐923. [PubMed] [Google Scholar]

Broex 2009

• Broex EC, Asselt AD, Bruggeman CA, Tiel FH. Surgical site infections: how high are the costs?. Journal of Hospital Infection 2009;72(3):193‐201. [PubMed] [Google Scholar]

Cutting 2002

• Cutting KF, White RJ. Maceration of the skin and wound bed. 1: Its nature and causes. Journal of Wound Care 2002;11(7):275‐8. [PubMed] [Google Scholar]

Deeks 2011

• Deeks JJ, Higgins JPT, Altman DG (editors), on behalf of the Cochrane Statistical Methods Group and the Cochrane Bias Methods Group. Chapter 9: Analysing data and undertaking meta‐analyses. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

DeMets 1987

• DeMets DL. Methods for combining randomized clinical trials: strengths and limitations. Statistics in Medicine 1987;6(3):341‐50. [PubMed] [Google Scholar]

DerSimonian 1986

• DerSimonian R, Laird N. Meta‐analysis in clinical trials. Controlled Clinical Trials 1986;7(3):177‐88. [PubMed] [Google Scholar]

Downie 2010

• Downie F, Egdell S, Bielby A, Searle R. Barrier dressings in surgical site infection prevention strategies. British Journal of Nursing 2010;19(20):S42‐6. [PubMed] [Google Scholar]

Dyson 1988

• Dyson M, Young S, Pendle CL, Webster DF, Lang SM. Comparison of the effects of moist and dry conditions on dermal repair. Journal of Investigative Dermatology 1988;91(5):434‐9. [PubMed] [Google Scholar]

Egger 1997

• Egger M, Davey SG, Schneider M, Minder C. Bias in meta‐analysis detected by a simple, graphical test. BMJ 1997;315(7109):629‐34. [PMC free article] [PubMed] [Google Scholar]

Garcia‐Gubern 2010

• Garcia‐Gubern CF, Colon‐Rolon L, Bond MC. Essential concepts of wound management. Emergency Medicine Clinics of North America 2010;28(4):951‐67. [PubMed] [Google Scholar]

Garner 1986

• Garner JS. CDC guideline for prevention of surgical wound infections, 1985. Infection Control 1986;7(3):193‐200. [PubMed] [Google Scholar]

Gurusamy 2009

• Gurusamy KS, Gluud C, Nikolova D, Davidson BR. Assessment of risk of bias in randomized clinical trials in surgery. British Journal of Surgery 2009;96(4):342‐9. [PubMed] [Google Scholar]

Gwosdow 1993

• Gwosdow AR, Cunningham JJ, Lydon M, Rascati R, Berglund LG. Evaporative water losses through a temporary wound dressing under simulated wound conditions. Journal of Burn Care and Rehabilitation 1993;14(4):450‐4. [PubMed] [Google Scholar]

Hasan 2009

• Hasan Z, Gangopadhyay AN, Gupta DK, Srivastava P, Sharma SP. Sutureless skin closure with isoamyl 2‐cyanoacrylate in pediatric day‐care surgery. Pediatric Surgery International 2009;25(12):1123‐5. [PubMed] [Google Scholar]

Higgins 2002

• Higgins JPT, Thompson SG. Quantifying heterogeneity in a meta‐analysis. Statistics in Medicine 2002;21(11):1539‐58. [PubMed] [Google Scholar]

Higgins 2011a

• Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Higgins 2011b

• Higgins JPT, Altman DG, Sterne JAC (editors) on behalf of the Cochrane Statistical Methods Group and the Cochrane Bias Methods Group. Chapter 8: Assessing risk of bias in included studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Higgins 2011c

• Higgins JPT, Deeks JJ (editors). Chapter 7: Selecting studies and collecting data. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Higgins 2011d

• Higgins JPT, Deeks JJ, Altman DG (editors) on behalf of the Cochrane Statistical Methods Group and the Cochrane Bias Methods Group. Chapter 16: Special topics in statistics. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Horan 1992

• Horan TC, Gaynes RP, Martone WJ, Jarvis WR, Emori TG. CDC definitions of nosocomial surgical site infections, 1992: a modification of CDC definitions of surgical wound infections. Infection Control and Hospital Epidemiology 1992;13(10):606‐8. [PubMed] [Google Scholar]

Hutchinson 1991

• Hutchinson JJ, Lawrence JC. Wound infection under occlusive dressings. Journal of Hospital Infection 1991;17(2):83‐94. [PubMed] [Google Scholar]

ICH‐GCP 1996

• International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use. Code of Federal Regulation & ICH Guidelines. Media: Parexel Barnett, 1996. [Google Scholar]

Keill 1973

• Keill RH, Keitzer WF, Nichols WK, Henzel J, DeWeese MS. Abdominal wound dehiscence. Archives of Surgery 1973;106(4):573‐7. [PubMed] [Google Scholar]

Kjaergard 2001

• Kjaergard LL, Villumsen J, Gluud C. Reported methodologic quality and discrepancies between large and small randomized trials in meta‐analyses. Annals of Internal Medicine 2001;135(11):982‐9. [PubMed] [Google Scholar]

Lawrence 1998

• Lawrence WT. Physiology of the acute wound. Clinics in Plastic Surgery 1998;25(3):321‐40. [PubMed] [Google Scholar]

Lefebvre 2011

• Lefebvre C, Manheimer E, Glanville J (editors) on behalf of the Cochrane Information Retrieval Methods Group. Chapter 6: Searching for studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Macaskill 2001

• Macaskill P, Walter SD, Irwig L. A comparison of methods to detect publication bias in meta‐analysis. Statistics in Medicine 2001;20(4):641‐54. [PubMed] [Google Scholar]

Merei 2004

• Merei JM. Pediatric clean surgical wounds: is dressing necessary?. Journal of Pediatric Surgery 2004;39(12):1871‐3. [PubMed] [Google Scholar]

Mertz 1985

• Mertz PM, Marshall DA, Eaglstein WH. Occlusive wound dressings to prevent bacterial invasion and wound infection. Journal of the American Academy of Dermatology 1985;12(4):662‐8. [PubMed] [Google Scholar]

Moher 1998

• Moher D, Pham B, Jones A, Cook DJ, Jadad AR, Moher M, et al. Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta‐analyses?. Lancet 1998;352(9128):609‐13. [PubMed] [Google Scholar]

Newell 1992

• Newell DJ. Intention‐to‐treat analysis: implications for quantitative and qualitative research. International Journal of Epidemiology 1992;21(5):837‐41. [PubMed] [Google Scholar]

NHS reference costs 2012

• Department of Health, United Kingdom. Financial year 2011 to 2012 reference costs published. http://www.dh.gov.uk/health/2012/11/2011‐12‐reference‐costs/ 2012 (accessed on 13 March 2013).

RevMan 2011 [Computer program]

• The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.1. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2011.

Schulz 1995

• Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995;273(5):408‐12. [PubMed] [Google Scholar]

Schünemann 2011

• Schünemann HJ, Oxman AD, Higgins JPT, Vist GE, Glasziou P, Guyatt GH (editors) on behalf of the Cochrane Applicability and Recommendations Methods Group and the Cochrane Statistical Methods Group. Chapter 11: Presenting results and ‘Summary of findings’ tables. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

SIGN 2013

• Scottish Intercollegiate Guidelines Network. Search filters. http://www.sign.ac.uk/methodology/filters.html (accessed May 24 2013).

Ubbink 2008

• Ubbink DT, Vermeulen H, Goossens A, Kelner RB, Schreuder SM, Lubbers MJ. Occlusive vs gauze dressings for local wound care in surgical patients: a randomized clinical trial. Archives of Surgery 2008;143(10):950‐5. [PubMed] [Google Scholar]

Wood 2008

• Wood L, Egger M, Gluud LL, Schulz KF, Jüni P, Altman GD, et al. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta‐epidemiological study. BMJ 2008;336:601‐5. [PMC free article] [PubMed] [Google Scholar]