Portal de Periódicos da CAPES

Evidence-based wound care in the UK

2009; Wiley; Volume: 6; Issue: 2 Linguagem: Inglês

10.1111/j.1742-481x.2009.00581.x

1742-481X

David Leaper,

Surgical Sutures and Adhesives

Evidence-based medicine (EBM), defined aptly in 1996 (1,2), is now part of established practice and here to stay; no-one could deny that it has raised the standard of medicine in the UK and the rest of the world where it has been recognised, enforced and made effective. It is, of course, logical that guidelines and protocols for clinical practices should be based on the best evidence available, particularly in the multidisciplinary area of wound care. However, poor quality EBM could be inappropriately used politically, and by non-clinical management, for the expedient control of waiting lists and waiting times; control of often poorly considered clinical governance sessions (although the establishment and value of multi-disciplinary meetings cannot be denied); and control of financially-driven targets rather than the optimisation of clinical outcomes and health care resources. In some ways this has detracted from the main function of EBM to genuinely improve practice for clinicians, carers and patients. Exploitation of inadequate EBM can also be used by the media, for example, to highlight the plight of individuals who have cancer and who are denied life-extending drugs, and also concepts such as 'post-code prescribing' in which some treatments are approved by some Primary Care Trusts but not by others. Nevertheless, some media campaigns have led to exposure of poor standards and ill-founded claims, although sometimes muddying the waters of EBM. So the need for high quality EBM is important. This has led to the need for accurate methods of assessment for EBM, and measurement of outcomes and economic evaluation, to ensure that there is cast iron scientific evidence for protocols and guidelines (3). In the field of wound care this has proved to be severely limited, where the gold standards of meta-analysis and randomised controlled trials (RCTs) are scarce. The grading and presentation of evidence for clinical implementation has developed in two general directions: first is the extensive identification and critical appraisal of all published and presented information, but only including adequately powered RCTs, with clear definitions, blinding and randomisation, in the report (as in a Cochrane systematic review (4)); and secondly is the approach which differs by including all levels of evidence, not only level I, in the assessment. The resulting compilation of this latter methodology is the key to producing a clinical guideline, as in the National Institute for Health and Clinical Excellence (NICE) and the Scottish Intercollegiate Guidelines Network (SIGN) (5,6), (the author of this article was a contributor to references 4–6 and reviews in other fields). This second approach also involves clinicians and scientists, who have an interest in the field, and undertake the analysis of all available material which is still graded for a level of excellence, but allows an expert opinion to be given for clinical guidelines particularly when evidence is weak. The principal difference is that Cochrane reviews do not necessarily have an expert panel, relying on scientific skills alone, and if the evidence is weak the review panel does not usually offer any guidelines. In the field of would care the amount of level I evidence is lamentably small and expert opinion for guidelines is critical, otherwise none would exist. There is no question of the excellence of the Cochrane review process and that its methodology is the most robust and rigorous on offer. The Wounds Group of the Collaboration has tackled many of the major and challenging aspects of wound care. So often however the evidence found is of poor quality and practitioners hungry for signposts are left uncertain and frustrated with a conclusion that indicates that 'more research is needed'. The lack of expertise on the panel is often reflected in distillations of the reviews in journals (7); although suggestions in this example that topical antibiotics or relatively unknown antiseptics may be used in chronic venous ulcer care (based simply on single, relatively poor RCTs) have been modified in a more recent Cochrane systematic review (8). There are several other Cochrane systematic reviews relevant to wound care but they all suggest, when there is no difference between reviewed topics, that more evidence is required (this list is not exhaustive): compression for leg ulcers (9); debridement for surgical wounds (10); and dressings and topical agents for surgical wounds healing by secondary intention (11). More controversially the reviews on silver caused difficulties (12,13) as guidelines are required for practitioners in this field; there is wide acknowledgement of the efficacy of silver dressings but an awareness of their additional costs and in this situation an "expert" evaluation, based on all evidence available, may be more helpful (14,15). Another unhelpful systematic review, of topical negative pressure therapy (TNP) for treating chronic wounds (16), was followed by a distillation in a journal publication (17) that claimed 'until a far more rigorous evaluation.… is completed the use of TNP should not become routine or be reimbursed for local wound care'. For many experienced practitioners this will be unacceptable as they are aware that TNP has saved lives and limbs. Admittedly an RCT in this field is fraught with difficulties but, despite any perceived shortcomings, at least one acceptable trial has been published in this field (18). The cost of such studies, to include all the requirements of an RCT, is prohibitively high and requires multi-centre evaluation to have any chance of completion. Only Industry could possibly support many of these studies and has done so extensively. Many fear that bias and conflict of interest devalue these publications, which leaves further research, and also guidelines, in a cleft stick. Where are the guidelines for wound care to come from if they can only be based on evidence-based medicine that incorporates the gold standards of the Cochrane Collaboration? NICE and SIGN have some catching up to do but guidelines have been produced, for managing pressure ulcers and chronic leg ulcers, which are being accepted into clinical practice (19–22). Other topics considered by NICE include diabetic and venous foot ulcers (both suspended), and NPT (some not considered in the NICE remit or in progress). In the meantime it is likely that guidelines will have to be produced locally taking in what is on offer from the Cochrane reviews, NICE and SIGN; but with local appraisal of all avenues of evidence from other published (opinionated) reviews, expert opinion and presentations and position documents from societies and committed groups. Several best practices have already been produced and published by the European Wound Management Association (www.ewma.org.), the World Union of Wound Healing Societies (www.wuwhs.org.) and the International Wound Infection Institute (www.woundinfection-institute.com.). A tongue-in-cheek paper has been written on the misplaced need for an RCT when the outcome is obvious (23). This is often the case in wound care and further Cochrane systematic reviews in this field are not likely to achieve much and guidelines will largely depend on "lower levels" of evidence or time-honoured practice. These will, of course, need periodic review to ensure that important new research is not overlooked. Another interesting communication, looking at the hierarchy of research design, has explored and shown that observational studies with either cohort or a case-controlled design do not systematically overestimate the effects of treatment (24). Several such studies, in wide-ranging fields, were compared with RCTs on the same topics and it was convincingly shown that they could be as useful and not, as widely believed, misleading or be a disservice to patient care or clinical investigation. This could be highly relevant to advances in wound care. A plea for acceptance of these diverse hierarchies of evidence and continued development of their methodology, rather than slavish commitment to the RCT, has also been made in a Harveian Oration (25). However, there still is an occasional reluctance to accept the basic tenets of evidence based medicine. Following a published summary of the NICE guidelines on the prevention and management of surgical site infection (26) a letter was received and published (27) which claimed that "the most important factors in wound infection were the skill and training of the surgeon, judgement, planning and avoidance of tissue damage and haematoma". Whilst these sentiments are largely shared, none of these qualities can be accurately measured nor have any of these anecdotal claims ever been tested for veracity in even the most simple of trials. For best practice in wound care the best evidence should be followed in guidelines based on the best scientifically produced and evaluated data available; in the meantime, and foreseeable future, the writing of most guidelines will continue to depend on all information available and its interpretation by expert opinion. Professor David Leaper 1 Visiting Professor