Tag Archives: Winter

Level 4

The question

Comment

There is one question wound care specialists typically do not ask. If Winter and Hinman proved the use of cling film speeds up wound healing by 40%, why are there hardly any studies repeating the phenomenon in a clinical setting and do meta-analyses invariably deliver hardly any or no effect.  It seems to me the gap between Winter (animal research, evidence level C), Hinman (evidence level B) +40% and meta-analyses  (evidence level A1) +/- 0% requires an explanation. To me it is a logical question for a logical problem: the gap is too large, we cannot find 40% and 0% outcome at the same time. So who sheds some light on the logic behind the phenomenon?

General

Low reproducibility rates within life science research undermine cumulative knowledge production

Comment

To cite the article below: “Low reproducibility rates within life science research undermine cumulative knowledge production“. Wound care research provides an excellent example. Quoting the EWMA Study Recommendations for clinical investigations in leg ulcers and wound care (2014) “However, we are all aware that the quality of many studies in this field remains poor and we would be doing a disservice as the European Wound Management Association if we did not encourage our members to join in the challenge of raising the quality of studies for the benefit of our patients.” This is 2015!

Wound care research more than often (def)end inconclusive articles with the phrase : “more research is needed”. The result may be inconclusive but the expert opinion is not, research was flawed because it does not proved the result the author was expecting based upon his or her expert opinion. In this little sentence you may already feel the importance of the expert opinion. It is interesting to notice meta analyses with conclusive results are put aside to the benefit of expert opinions. The expert opinion is leading in wound care. This means the wound care specialist concludes the meta analyses are based on wrong data and prefer their own opinion (expert opinion).

The “expert opinion” leads to the following observation: either it is impossible to do wound care research or we have a massive logical error preventing us to come up with widely accepted meta analyses. Anyway, following the international guidelines meta analyses are leading, not the expert opinion. But no matter who is right, in 2015 we still are using the same paradigms as in 1943.

So the conclusion of this article is valid for wound care; yes, there has been no cumulative knowledge production in wound care. (for 70 years)

Freedman LP, Cockburn IM, Simcoe TS (2015) The Economics of Reproducibility in Preclinical Research. PLoS Biol 13(6): e1002165. doi:10.1371/journal.pbio.1002165
http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002165
http://ewma.org/english/publications/ewma-documents-and-articles/ewma-study-recommendations.html
E L Howes. The rate and nature of epithelization in wounds with loss of substance SGO 1943 Vol 76 (738-745)

below are two random articles, feel free to do your own research…
http://www.woundsresearch.com/article/real-world-experience-decellularized-dehydrated-human-amniotic-membrane-allograft
http://www.magonlinelibrary.com/doi/10.12968/jowc.2015.24.6.245

Level 4

Reverse evidence

Comment

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.