Title: A pragmatic multicentre randomised controlled trial to assess the clinical and cost effectiveness of negative pressure wound therapy versus usual care for surgical wounds healing by secondary intention (SWHSI 2)
Funder: Department of Health and Social Care

Abstract: DESIGN: Multi-centre, cross surgical specialty, two-arm parallel group, pragmatic, randomised controlled trial, with internal pilot, to assess the clinical & cost effectiveness of negative pressure wound therapy (NPWT) versus usual care (no NPWT) as a treatment for surgical wounds healing by secondary intention (SWHSI). Randomisation will be completed by York Trials Unit’s secure web based service, ensuring adequate allocation concealment, using a 1:1 ratio stratified by wound location (foot/leg, abdomen, other). SETTING: Secondary & community NHS Trusts & primary care centres. POPULATION: Consenting adults with a SWHSI ready & appropriate for NPWT or wound dressing treatment, receiving adequate nutrition will be eligible. Patients contraindicated to NPWT, previous receipt of NPWT on the wound & wounds non-surgical in origin, will be excluded. TECHNOLOGY TO BE ASSESSED: Intervention: NPWT devices in use in the NHS. Control: Any dressing without NPWT (usual care). The clinical care team will determine NPWT device or dressing type & treatment regimen. OUTCOMES: Primary; Time to healing in days since randomisation (i.e. complete epithelial cover in the absence of a scab), verified using standardised photographs by independent blinded observers. Secondary; Clinical & adverse events, wound infection (Bluebelle WHQ (3)), pain, Quality of Life (EQ5D-5L (4)) & resource use. ASSESSMENT: Epidemiological data including comorbidities, smoking status, and surgical procedure detail (e.g. urgency and contamination level) will be collected at baseline. Randomised patients will be contacted weekly to monitor wound healing and other clinical and adverse events. Where healing is self-reported by the participant three visits on consecutive weeks will be made and photographs taken for blinded outcome verification. EQ5D-5L, wound pain, infection (Bluebelle WHQ) and resource use will be assessed at 3, 6 and 12 months by postal questionnaires. ANALYSIS: Primary analysis will assess time to healing using Kaplan Meier curves and Cox Proportional Hazards regression models with shared centre frailty effects, adjusting for baseline wound size, duration and location. CACE analysis will assess treatment effects in the presence of non-compliance. Secondary outcomes will be analysed using appropriate regression techniques. The economic analysis will assess cost effectiveness. A decision analytic model will be generated to incorporate evidence from the existing evidence base, and from the trial to establish which of the relevant treatment(s) are most cost-effective. SAMPLE SIZE: To detect a 25% reduction in median time to healing (from 86 days with standard care to 65 days with NPWT), with 90% power, and allowing for 20% attrition, the total sample size required is 696 participants (348 NPWT; 348 Usual Care). PROJECT TIMETABLE: Total project duration - 48 months - Set-up; 6 months - Internal pilot; 6 months, 10 sites recruiting 1-2 patients/month (100 participants) - Full recruitment; 18 months, 20 sites recruiting 1-2 patients/month (596 participants) - Follow up; 12 months - Data cleaning, analysis & reporting; 6 months. PROJECT TEAM: Our multidisciplinary team will build on experience in recruiting, retaining & collecting data from SWHSI patients, developed through work over the past 5 years on the NIHR PGfAR (RP-PG-0609-10171). Our project team includes surgical specialty leads, and we have developed links to the MRC ConDUCT-II Hub.

Lay abstract: BACKGROUND: After an operation, most wounds are closed using stiches or staples. Some wounds cannot be closed in this way and are left open. Sometimes wounds that have been closed may open up again. These “open” wounds are usually left to heal, over time, from the bottom up rather than attempting to close them again by some other means. Funded by a government grant, over the last 6 years, our research group has carefully studied patients with these open surgical wounds. We have identified the types of surgery that most frequently lead to these wounds. We have also found that open surgical wounds often take many months to heal, can be painful and smelly, and may release a lot of liquid (wound fluid) that is difficult to manage. The most common treatment for these wounds is plain dressings. People with open wounds are at high risk of on-going issues (e.g. infections and needing more surgery); often say they feel depressed and isolated and may have difficulty working leading to financial problems. People with open wounds are usually desperate for their wounds to heal and are often willing to try any treatment that promises quicker wound healing. Negative Pressure Wound Therapy (NPWT) is a relatively new treatment for open surgical wounds. It uses a small machine to apply gentle suction to a wound through a special dressing. This removes wound fluid, may keep the wound clean and may help with healing. Use of NPWT has become more common and is used in around one third of people with open surgical wounds. We don’t know if NPWT is as good as, better than or worse than normal wound dressings because there has not been enough independent research to enable doctors and nurses to decide if or when this is the best treatment. Patients report both positive and negative experiences of NPWT. Patients like that NPWT means they need fewer dressing changes and may lower the risk of infection. However, they also say that dressing changes can be more painful, that NPWT limits how well they can move about and get out because it is bulky and can be embarrassing, and that the noise of NPWT disrupts their sleep. Doctors and nurses are generally positive about NPWT dressings; however, it is expensive and costs the NHS millions of pounds each year. AIMS: We want compare NPWT with normal dressings to see if it makes any difference to how quickly these open wounds heal. METHODS: We will form two groups of patients with open surgical wounds by a process called randomisation – which means that the group which patients go into is based on chance (e.g. on the toss of a coin) rather than the patient or their doctor deciding. One group will be offered NPWT, the other normal care. We will compare what happens to the two groups over 12 months including: how long it takes peoples' wounds to heal; other important events such as number of infections, hospital admissions and further operations; and how much both treatments cost. PATIENT AND PUBLIC INVOLVEMENT: Our established patient advisory group and patient co-applicant will continue to be central to trial design, management and reporting. DISSEMINATION: Our results will be presented and published nationally and internationally guiding patients, doctors and nurses, and health care providers about the use of NPWT and other treatments for open surgical wounds in the UK and globally. Our patient group will help create lay summaries of our findings for trial participants and the wider population.

Research activity codes: 6.3 MEDICAL DEVICES
Health categories: SKIN