COAT

Important things to know about the COAT study 

People with cellulitis of the leg are being invited to take part. Your healthcare professional will discuss with you whether you are eligible to take part or not. 

Cellulitis is a deep skin infection. Most people with cellulitis in the U.K. are treated with the antibiotic flucloxacillin for 7 days. However, research studies show that short courses of antibiotics (5 days or less) work as well as longer courses for many different types of infections, including serious infections like pneumonia. For cellulitis, there have been some studies that have shown that short courses work as well as longer course, and U.K. guidance recommends a 5–7-day course. However, there have not been any studies comparing short and longer courses of flucloxacillin prescribed outside of hospital settings (i.e. GP surgeries). Taking longer courses of antibiotics is likely to cause more side effects and kill off the ‘good bacteria’ that help keep us healthy.  

The symptoms of cellulitis, like redness and swelling, are unlikely to have completely cleared by 5 days or 7 days. However, symptoms usually last longer than the actual infection. We want to see if the symptoms of cellulitis continue to get better in a similar way in people who take 5 or 7 days of antibiotics. Specifically, we want to make sure that people who take antibiotics for 5 days do not have more pain than those who take them for 7 days.  

To watch a video explaining the study and for further information, please CLICK HERE  which will take you to the study webpage: 

Depending on the location that you are treated at for your cellulitis, your journey through the study will follow one of the 2 pathways below: 

 Pathway 1 

You will be asked to provide consent by signing a paper form with the healthcare professional at your initial consultation. Your GP will be informed of your participation in the study. 

 Pathway 2 

We will ask you to provide consent using an electronic consent system. You can complete this during a phone call or video call with  a member of the central COAT study team who will guide you through the electronic consent system. Your GP will be informed that you are taking part in the study. 

Both pathways 1&2 

You will then be asked to answer a few questions about yourself and your illness.  

Your healthcare professional will prescribe an antibiotic (flucloxacillin) for you to take for five days. You will then be sent a pack containing capsules to take for a further two days. This pack will contain either antibiotic (flucloxacillin) or a placebo (dummy pill) and will look different from the capsules you were taking for the first 5 days. Please note that the study capsules contain gelatine. You will not know whether you have been given the antibiotic or placebo and the chance of treatment with either a 7-day course or a 5-day course is equal. 

You will also be asked to fill out short online questionnaires about your cellulitis at the following times: 

• Details about your illness and background (like gender and ethnic group) in an initial questionnaire (this may be completed at the time you join the study if you are in Pathway 2). 

• Then very brief questions about your illness every day for up to 13 days. 

• A few additional questions once a week for the first 4 weeks. 

These questionnaires will be sent to you by an SMS (text message) or email link to an online form, or can be completed on paper. If completed on paper, we will provide you with pre-stamped envelopes to send the questionnaires back to us. In the unlikely event that your paper questionnaires do not arrive to your home address, we may contact you to collect the questionnaires over the telephone. We will also ask for your permission to review your medical records 12 months after you joined the study. This is to see if you developed any complications or recurrence of your cellulitis. We won’t need to contact you about this. 

Your responses to the questionnaires will only be seen by the study researchers and will not be seen by your healthcare professional. Therefore, if you have any concerns about your health you should report these to your GP surgery, NHS 111, or emergency services as you would if you were not in the study. They will be able to assess and treat you as necessary, including providing additional antibiotics if necessary.