A question of evidence

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The diversity of wounds and the wounded means that the evidence base for wound care therapies is a complex issue. Professor Richard White of the University of Worcester and Wound Care Alliance UK looks at how companies can best establish the case for their products.

The current situation regarding issues of product evidence and product availability in wound care has been discussed in Medtech Business (May and June 2010). Therapies affected by these issues include silver and other modern wound treatments, such as moist wound healing dressings and topical negative pressure (TNP) devices, which have attracted the scrutiny of those who conduct systematic evidence reviews. Following those commentaries, this article offers some proposals for a way forward.

Therapies on trial

The modern age in wound care, dating from around 1970, has seen a variety of new medical devices come to market – many of which have achieved ‘standard of care’ status. For example, elastic and non-elastic compression bandaging; hydrocolloid, alginate, foam and film dressings; honey as a CE Marked product and many others have become established in the clinical armamentarium.

Countless clinicians, many of them acknowledged experts, have come to rely on these products, knowing that when they are correctly used they work well. This steady supply of products has come from an innovative, dynamic industry that works closely with the clinician.

However, the evidence gathered to support these products does not satisfy the various groups who insist on the Cochrane-style analysis of randomised clinical trials (RCTs). Recent publications have criticised the evidence for moist wound healing, antiseptic dressings and TNP. This criticism, published in the medical literature and the national press, has led to restrictions on product availability.

The key priority, in my view, should be to maintain a regular flow of safe and effective innovations, supported by sufficient evidence for regulatory purposes and for informing the clinician. The introduction of such products should, of necessity, be followed by the ongoing collection and publication of clinical evidence.

Innovation is vital to wound care, as the steady flow of new and improved products leads directly to better patient care. The discipline is still in its infancy – a stage when developments are frequent. The industry is populated by a broad mix of large, established companies and smaller companies, many of them start-up ventures. This affects the level of investment available for expensive RCTs.

Should trials be left to the wealthy companies alone? Or can other, more economical forms of clinical evidence be gathered instead? That would offer the smaller, less affluent companies greater opportunity to develop products, gather evidence and take their treatments to market – and in the past, that has been a significant feature of wound care in the UK.

There is no doubt that evidence in one form or another is essential for the development of wound care – so open discussion of the issues around what makes for effective evidence is needed. In addition, some proactive action on the part of the wound care sector is also essential: companies must, to my mind, take action before further restrictions in product availability are foisted upon them.

Finding the facts

There is a strong case for looking more carefully at what evidence is already available in the public domain. Cochrane analyses have been justly criticised for not taking all of the available evidence into consideration. A preferable method of analysis, with recommendations, is the GRADE system. This well-known and respected system, in my opinion, should be employed to assess the evidence for a number of existing products.

With regard to the ‘quality’ of different types of evidence, the European Wound Management Association (EWMA) has published guidelines for the conduct of RCTs in the May 2011 issue of the Journal of Wound Care.

If a company decides that an RCT is the most appropriate means of gathering clinical evidence, it is important that they avoid the pitfalls which have blighted many previous trials. The Cochrane reviews list the numerous shortcomings in trials, mainly methodological errors, which form grounds for disqualification. These can be avoided!

  • At the planning stage, trials should be configured with purchasers in mind: as well as gathering clinical information, the trial should take account of economic factors and quality of life instruments.
  • Once the data are published, these should enhance the chances of product uptake or changes in clinical practice. Quality data will make counter-arguments difficult and merit publication in quality journals, and so garner support from opinion leaders.

Case studies are frequently used to provide support for products. However, it is an unfortunate fact that many, probably most, of these studies are of very little value. This is due to their planning and objectives, as well as the information provided. When case study posters and journal reports make products appear to be panaceas, it is no wonder that the whole exercise becomes devalued.

Cohort studies, when properly conducted, can be valuable in many ways. Their merit has been extolled by many influential figures. The GRADE system of analysis gives reasonable weighting to such studies, whereas Cochrane analyses ignore them completely. Their format is less clear than that of RCTs – but when they are conducted in a multicentre setting, with clear objectives and endpoints such as clinical goals, economic factors and quality of life issues, they provide useful data.

Post-marketing surveillance studies, conducted long-term in the ‘real world’ of routine clinical practice, are under-used and under-estimated in wound care. As far as I am aware, they are mandatory in Germany and some quality data have been published from these studies.

Audit of clinical practice is as ‘real world’ as we can get when it comes to clinical (and hopefully financial) data. Efficient clinical settings can audit their practice for long-term outcomes in treatment of wounds. Such studies can provide the most meaningful evidence.

Value and cost

Cost-effectiveness, or health economics, has been a high priority in healthcare for many years, yet it does not figure in enough wound studies. Rather naively, claims of ‘cost-effective’ based on the unit price of a product still appear.

Health economics is a defined and refined science and must be recognised, and used, as such. In this respect there is vast room for improvement in company-sponsored wound treatment studies.

For the future, it is important that the evidence for wound care therapies is of better quality than it generally has been over recent decades. This is achievable through awareness of the literature and close liaison with experts – it does not necessarily need to incur substantially greater costs!

The whole dynamic of selling has changed over the past twenty years. No longer is it sufficient to demonstrate the product to a nurse or doctor and wait for the orders to flow in. Other key groups are now involved, and liaison with them to facilitate product uptake has become essential.

Everyone involved in wound care in the UK must now be aware of, and recognise the important role of, pharmacists, medicines management, formulary committees etc. Companies must do more to involve these groups.

The transition or evolution of standards for medical devices from the days of the first modern ‘moist wound dressings’ is remarkable. Following the enactment of the Medical Device Directives in the mid-1990s, the system has become more ordered and bureaucratic.

However, this process is far from complete. The recent furore over failing hip implants has shown that the current regulations are not adequate to prevent major clinical catastrophes involving medical devices. In the USA, the FDA is taking a very close look at device regulation.

As the standards for evidence become more sophisticated, better reflecting the realities of clinical practice, the medical device industry – and in particular, the sector supplying wound dressings and associated products – has the opportunity to address the need for change and adapt accordingly.

Richard White is Professor of Tissue Viability at the University of Worcester.