Reverse evidence

Since 1962 we all know that wounds without a scab heal 40% faster compared to wounds with a scab. This has been tested on two pigs (Winter, Nature 1962) and seven inmates (Hinman, Nature1963). This means, since 1962, we all are convinced that a for instance diabetic wound on an 83-year-old will heal up to 40% faster, only if you apply a moist environment.

Reversibly you may also try to answer the question how much slower wounds would heal if you would use of moist gauze, which have to be changed up to 3 times a day. Almost 50 years after Winter some people have tried to answer this question (Ubbink DT et al, Arch Surg 2008). What appears was that moist wound healing was not better but actually worse than a conventional gauze treatment. But there was one remark, these findings apply only for wounds with an acute etiology (and in a hospital setting).

Ehh well yess…. what type of wounds were investigated in the Winter and Hinman papers?

But fair is fair, one study should not make a difference, scientific principles dictate a finding should be repeated several times in order to be accepted.

This is why we have organisations which examine the evidence. One of those organisation is the Cochrane foundation which has as purpose to help medical professionals in their decisions. The method they use is to ruthlessly examine all research papers against the highest standards. <http://www.cochrane.org/about-us>. And nothing is easier than to go to their website and read what they have to tell about wound care.

If I cite them randomly: negative pressure therapy, there is not enough evidence. (And it is not only Cochraine but also for instance Vig S et al, J. of Tissue Viability 2011), Alginate; there is no evidence that alginate is better than any other addressing, foams; conclusion is the same, no evidence. The only exception appears to be hydrogel were the conclusion is that hydrogel is have some evidence to be more effective compared to other dressings. Silver dressings, no evidence etc. After a quick glance I counted 105 studies with almost 10,000 patients which actually met the Cochrane criteria.

Cochrane provides one, real unnerving outcome, no one is able to prove or repeat the 40% faster promise from the original articles more than 50 years. Apparently it is not possible to design a study or do a study which is meeting current scientific criteria and show a 40% faster healing.

So we start reducing our expectations. Perhaps we are asking too much my looking for a 40% faster healing, so let’s settle for 20%, 10% or even 5%. That appears fair to me.

But even that is not possible, the most positive statement in these studies is “there is some proof”, which is quite different from 5% faster healing. Apparently it is not possible for any current wound care dressing to prove in a well-designed study it actually makes sense to use.

Now what, it appears we have a problem.

We are not able to prove how much a wound benefits from using a moist dressing. The next step would be to reverse the question, does it actually work? The answer to this question is very easy to answer, because there are plenty studies, meeting the highest scientific standards providing the answer, the Cochrane collection from above. The significant answer meeting the highest standards is: a moist environment does not lead to faster wound healing.

And this finally leads us to the heart of the problem. We have a Mexican standoff between 2 pigs, seven inmates and 285 clinical patients. I don’t believe that the Winter and Hinman articles were wrong. It doesn’t take rocket science to understand why a scab might be hindering wound healing progress. But I also don’t believe that the Cochrane findings have to be dismissed because they don’t fit our view on today’s wound care. It does mean we have a gap in our knowledge. The gap can be summarised as we are not able to explain why Cochrane and Winter are both right.

Interesting is that all stakeholders in wound care should be aware of this gap since there have been no repeating studies which proof the moist paradigm in different circumstances.

For some reason we have chosen to ignore this issue for the last 50 years which sadly also lead to 50 years of “less useful” research which papers invariably end with the conclusion “more research is needed”.

To me it appears we have some work to do.

To paraphrase: if not me, who… if not now, when.

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