Outcomes for people with infected diabetic foot ulcers are poorer than previously thought

New research published in the journal Diabetic Medicine, has shown that people with diabetes and an infected foot ulcer have worse outcomes than previously thought. In the first year after being seen at a clinic with an infected ulcer, 15.1% of study participants had died and 17.4% had had an amputation of part or all of their foot.

The study, published by Dr Mwidimi Ndosi and colleagues, set out to examine the outcomes for people with infected diabetic foot ulcers and the results underline the need for people at risk of foot ulcers to be closely monitored.

Diabetes mellitus, a group of diseases that affect the body’s ability to regulate blood sugar, can result in damage to several organs as well as blood vessels and nerves.

At least 3.6 million people in the UK have been diagnosed with diabetes and another million likely have the condition but have not been diagnosed. The number of people with the diabetes is rising and is set to increase further, largely related to the growing obesity epidemic.

About a quarter of people with diabetes will develop a foot ulcer (open skin wound) as a complication of the disease. Over half of these ulcers become infected, which often requires hospital admission and may end up with a lower limb amputation. Scientists estimate that every 20 second, somewhere in the world a person requires a leg amputation because of diabetes.

The new study, led by Professor Andrea Nelson at the University of Leeds, followed the outcomes of 299 people enrolled in the study at one of 25 centres in England. The results showed that after 12 months, the ulcer had healed in only 44.5% of the patients. This is a worse healing rate than has been observed in a comparable European multicentre study, where 77% ulcers had healed.

This new UK study is the first to estimate the rate of healing of infected diabetic foot ulcers and to identify which factors are associated with healing, whilst accounting for potential risks of amputation and death. “Without adjusting for these events, we would have overestimated the occurrence of healing in our study by almost 10%,” noted the study’s Senior Statistician, Alex Wright-Hughes, based at the University of Leeds.

The three key factors that were found to be the best predictors of healing were the adequacy of the blood supply to the foot, the absence of multiple foot ulcers, and how soon the patient was referred to the clinic.

People with diabetes should have an assessment of their risk of developing a foot problem when first diagnosed, and then at least annually if any foot problems arise. This, combined with education on how to prevent or deal with a foot ulcer, can help avoid bad outcomes.

“The results of our study are important and should help clinicians caring for patients with diabetes to identify those most at risk for poor outcomes so that we can look to provide further support,” said Dr Michael Backhouse, a Senior Research Fellow and podiatrist and co-author of the study.

The UK’s National Institute for Health and Care Excellence recommends that each community have a foot protection service, led by a podiatrist with specialist training, to help prevent or treat diabetic foot problems. The goal is to not only teach patients good foot care, but what to do if they find a problem. It is particularly important that patients quickly present for treatment if they have signs of infection of the foot.

Dr Benjamin Lipsky, Professor of Medicine and infectious diseases specialist based at the University of Oxford and a study co-author noted that “it is almost always infection that immediately leads to amputations. If quickly diagnosed and properly treated with antibiotics (and limited surgery), most infected ulcers can be healed.”

Dr Ndosi, Senior Lecturer at the University of the West of England, Bristol is the lead author of the paper and was the clinical coordinator of this nation-wide study.

“Our study recruited participants from centres ranging from large teaching hospitals to small primary healthcare clinics, so our results are likely to be representative of expected outcomes for people with diabetes and foot ulcers across England, and perhaps in other higher-income countries,” commented Dr Ndosi.

The results of the study can be accessed online: Ndosi M., Wright-Hughes A., Brown S, et al (2017) Prognosis of infected diabetic foot ulcers: A 12-month prospective observational study. Diabetic Medicine. ISSN 0742-3071 Available from: http://dx.doi.org/10.1111/dme.13537

Funding acknowledgement

This research was funded by the NIHR Health Technology Assessment Programme, HTA 09/75/01. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

Further information

For more information, please contact David Lewis, media relations officer, University of Leeds; +44 113 343 8059 or email [email protected]