Tackling the Evidence Elephant in Chronic Pain Research

October 29, 2015

Good morning.  Coffee is in hand, and I’m wanting to quickly make a few comments about the complex topic of addressing treatment evidence in treating chronic pain.  First of all I want to point out that the very nature of this topic starts my mind glazing over even with the presence of delicious coffee in hand.

I’m not a statistician.  Even reading articles that delve into evidence and measures is tough for me. I am much more inclined to think about effectiveness in terms of what I experience in my clinic, directly.

So, I want to point out that there is a good article in the August 2015 APTA ( American Physical Therapy Association) Journal on this very topic titled Interpreting Effectiveness Evidence in Pain: Short Tour of Contemporary Issues.

Here are a few ideas from this article which you may find valuable in your practice.  There are 2 terms to be aware of.  One is efficacy which addresses clinical trials in optimum conditions.  The second one is effectiveness which is about seeing if something works in the real world which is your clinic.

The body of the article delves into the specifics of the complexities and reasons why clinical trials rarely give us any concrete clarity in treating chronic pain. I can’t clearly summarize that discussion well enough to try. If you want that level of mental engagement read the article.

What I love is the acknowledgement that the holy grail of clear evidence of efficacy and effectiveness is not going to show up anytime soon in the field of chronic pain treatment.  And I’m not going to wait around for it either.  That’s just the nature of it and it is reasonable to accept that you can’t wait for the evidence to show up to engage in efforts to improve treatment outcomes.

One measure that is useful is what’s called a minimally clinically important difference (MCID)1. Another is smallest worthwhile effect (SWE)2 that a patient is happy with. Your clients who have been through many other significantly underachieving treatments serve as their own control.  Their symptoms have endured as largely unchangeable. You are the provider who will guide them over the significance threshold.

These measures are individualized and reflect real perceived improvement in a clients quality of life in dealing with their pain.  A general range of relevance is at a minimum 30%.  This is acknowledged to be an arbitrary cut off.  If a client is in a severe situation, perhaps for them even a 20% noticeable reduction is an important milestone.

When you work with chronic pain conditions, you may be seeing clients who have been through other interventions and seen by many other providers. Some of those providers may also have been Physical Therapists.  You can get some idea of what else a client has previously tried in your history and their narrative.

This enables you to make a clinical decision that might take you into new territory.  You would be justified in not taking your client back through previously  presented therapies. Try something else.   The suggestion of the authors of this article, is to at least have a solidly based “biological plausibility” for what you do. Secondly they suggest limiting possible interventions to those with “rigorous evidence of effectiveness”.

Now unfortunately, you are right back where you started from with the failures of research to be able to provide  the “rigorous evidence of effectiveness”. You can keep learning and observing working towards MCID and SWE.

I believe that what you observe and create for healing in your clinic can be identified in the terms of MCID and SWE concepts.  Clients who invest their time and money to be treated don’t stick around if they aren’t getting a measurable improvement.

The article ends with comments that we need to maintain a level of dispassionate observation, acceptance of our own biases, and an eye to evidence.

I will end this note sharing a quote from the article. Epidemiologist Archie Cochrane says ” …be delightfully surprised when any treatment at all is effective, and always assume that a treatment is ineffective unless there is evidence to the contrary.”3

Your clinic is your vital stage for creating significant healing in your toughest cases.  At the end of the day what provides your deep satisfaction is feeling inside yourself that you have made a difference in a profound way for someone who is suffering.

If I can help you do this better, then my goal of sharing forward what I’ve learned is being achieved.

Thanks for taking your time to read this.


1) Jaeschke R, Singer J, Guyatt GH. Measurement of health status: ascertaining the minimally clinically important difference. Control Clin Trials. 1989;10:407-415.

2.)Ferreira ML, Herbert RD, Ferreira PH, et al. A critical review of methods used to determine the smallest worthwhile effect of interventions for low back pain. J Clin Epidemiol. 2012;65:253-261.

3.) Cochrane AL. Effectiveness and efficiency: random reflections on health services. Published June 1, 1972. Reprinted 1999. Available at http://www.nuffieldtrust.orguk/publications/effectiveness-and-efficiency-random-reflections-health-services. Accessed March 29, 2015.

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