All Evidence Is Not Created Equal: What Makes Good Clinical Data? Editorial Summary There were an estimated 3.8 million patients with a wound managed by the NHS in 2017/ 2018, of which 70% healed in the study year.1 The annual NHS cost of wound management was £8.3 billion, of which £2.7 billion and £5.6 billion were associated with managing healed and unhealed wounds, respectively.1 The annual prevalence of wounds increased by 71% between 2012/2013 and 2017/ 2018. This article explores clinical data in wound care.
Introduction
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Ms Kara Couch President-Elect, Association for the Advancement of Wound Care Associate Research Professor of Surgery, School of Medicine and Health Studies, George Washington University. Director, Wound Care Services, The George Washington University Hospital Arlington VA, United States
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ne cause of chronic wounds are diabetic foot ulcers (DFUs) - there were an estimated 326, 000 diabetic foot ulcers, which equates to 9% of all adult diabetic patients having a foot ulcer in the study year 2017/ 2018. Additionally, many of those patients with other causes of chronic wounds (e.g. non-healing venous leg ulcers) are also diabetic.1 In the United States, the total number of prevalent cases of DFU was 4,551,498 cases in the year 2020. Unhealed ulcers and foot infections are the leading cause of diabetes related amputations, with diabetic foot ulcers preceding 85% of amputations.2 In the United States, DFU patients are twice as costly to US Medicare as those with diabetes alone. The rate at which major amputations occur in a population with diabetes can be used as a good overall proxy measure of the effectiveness of health care and the foot care system for patients with diabetes.3 Survival rates have been found to be poor following a major amputation – the five year mortality for a diabetic patient following major amputation is 68% (compared to only 15% for breast cancer).4-5 There were 7,957 major lower-limb amputation procedures for patients with diabetes in England between 2017/ 2018 and 2019/ 2020 – this made up 51% of all lower limb amputations in England in this period.3 There were 21,738 minor lowerlimb amputation procedures for patients with diabetes in England between in the same period, with diabetic patients representing 69% of patients in this group.3
estimated at between £837 million and £962 million; 0.8% to 0.9% of the National Health Service (NHS) budget for England.6 More than 90% of expenditure was related to ulceration.6
How Is Evidence Graded? The evidence pyramid is a useful visual representation of the internal validity of different study designs; designs of low internal validity are at the base of the pyramid and designs of high internal validity are at the top (Figure 1).6 While the evidence pyramid is a useful guide, it is important to recognise it has limitations.6 When considering evidence in the context of the evidence pyramid, it is important to consider the goal of the research project: to understand the effects of treatment where high internal validity is a key requirement or to seek to make new discoveries and find explanations for the causes of disease.6 Where the goal is to understand the disease aetiology, the traditional research pyramid may be reversed, with case reports and case series providing useful data to start an exploration of disease causation.6 This may be especially valid in the case of rare diseases or harms where there are few patients with the condition available for recruitment into high internal validity studies, such as randomised controlled trials (RCTs).6 However, the evidence pyramid provides a simple overview of study designs that may have high internal validity and, as such, may impact or change clinical practice where a clear relationship is found between a treatment and clinical outcome.6
The cost of health care for ulceration and amputation in diabetes in 2014-2015 is
Wound Masterclass - Vol 1 - December 2022
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