Title: Multicentre non-inferiority cluster randomised trial testing Disposable versus Reusable drApes and Gowns for green OperatiNg theatres.


Background: The World Health Organisation makes no recommendation for the use of disposable or reusable surgical drapes and gowns due to a lack of effectiveness evidence. Since disposable versions are likely to have higher financial and carbon costs, they are only justifiable if they can be proven to significantly reduce surgical site infections (SSIs).


Aim: This randomised controlled trial will assess whether reusable surgical drapes and gowns are non- inferior in reducing SSI compared to disposable drapes and gowns in patients undergoing surgery.


Design: Pragmatic 1:1 international multi-centre non-inferiority cluster randomised controlled trial, with an internal pilot. Clusters are individual hospitals.



  • Clusters: Hospitals where there is clinical and organisational equipoise to randomise between disposable and reusable drapes and
  • Participants: Patients (adults and children) undergoing surgery with incision of at least ≥5cm in adults and ≥3cm in children aged under 16 years, with a clean-contaminated or contaminated/dirty wound. Participants undergoing emergency or elective, and open or minimally invasive surgery are eligible.


Intervention: Reusable surgical drapes and gowns.


Comparator: Disposable (single-use) surgical drapes and gowns.


Primary outcome: The primary outcome is surgical site infection (SSI) within 30 days after surgery, evaluated based on US Centre for Disease Control criteria.


Sample size: The control group SSI event rate is estimated to be 12.5% based on previous literature. To determine whether reusable drapes and gowns are non-inferior to disposable drapes and gowns with a non-inferiority margin of 2.5% would require a total of 26,800 participants from 134 clusters, with an average of 200 participants per cluster, assuming 90% power, 2.5% one-sided alpha, intraclass correlation of 0.01 and 5% participant loss to follow up.

DRAGON Lay Summary

Can we make operations in the NHS more environmentally sustainable?

What is the rationale behind our study?

Operating theatres are a significant source of a hospital’s carbon emissions, accounting for at least 25% of the total. Carbon emissions refer to the release of carbon dioxide and other greenhouse gases into the atmosphere due to various activities. These gases trap heat in our planet’s atmosphere, causing it to warm up and leading to serious changes in climate which can lead to catastrophic events like flooding and heat waves. In operating theatres, a substantial portion of these emissions results from the use of anaesthesia gases. However, even the solid waste generated in operating theatres also contributes to carbon emissions.


What do we want to do?

We want to find out if there are ways of lowering NHS Trust operating theatres’ carbon output without compromising patient safety. Specifically, we want to compare the impact of using disposable (single use) surgical drapes and gowns with that of reusable ones, both of which are commonly used in the UK and worldwide, in terms of reducing surgical infections. Disposable drapes and gowns are known to have a higher carbon footprint compared to reusable ones. However, there is currently a lack of strong evidence or guidance available to help clinicians determine the best option.


How will we achieve this?

We will run a trial that aims to prove that reusable surgical drapes and gowns are just as good as disposable ones at preventing surgical infections. We will also look at the carbon footprint and cost of using each in different NHS Trusts. Since implementing a change in the type of surgical drapes and gowns used involves making system-wide changes within the hospital, requiring cooperation from multiple departments, we will conduct a cluster randomized trial. In this trial, individual patient consent will not be sought; instead, blanket consent will be obtained from the participating NHS Trusts on behalf of the patients who will undergo surgery while the trial is ongoing.


Who are we?

We are a multidisciplinary group of surgeons, anaesthetists, public health professionals, sustainability experts, implementation scientists and community engagement specialists based at the University of Birmingham, Queen Elizabeth Hospital and Queen Mary University London who want to make the delivery of care in the NHS environmentally sustainable.

Key documents

  • Protocol: available shortly
  • Patient information sheet: available shortly