Explaining Pain for Acute Back Pain – reflections on Traeger et al. part 1

The PREVENT trial published recently in JAMA Neurology seems to have created a storm. If  views and tweets and general social noise are your metric, then this one weighs in pretty well – over 15K views and altmetric score passing 260 inside a week. But if impact on the community and likelihood to move the field forward is more your thing, then this one needs some serious soul searching and solid peer review, at least it does for me. Not because it is not an important trial – I think it is – negative trials are critical particularly when they show that a well thought through approach doesn’t shift the natural course of a condition. My response is more related to the response the paper has received – it runs the risk of getting belted beyond recognition by its own coverage. I was really excited by the results and I was keen to marry my commitment to scientific process (and therefore reporting in focus the one measure we were powered for), with my view that the a priori planned secondary analyses – genuine hypothesis-generators – suggest some remarkable possibilities that we should investigate.

What do I mean by ‘getting belted beyond recognition’? Well, I have received a very large number of emails, phone calls and passed-on Tweets, some from distressed ‘explain painers’, some from confused or annoyed clinicians, some from jubilant biomedicalists, some suggesting we just need to do more explaining pain, others suggesting we should drop it altogether, and just a few thinking deeply about the best way to move forward from here. I don’t think this study needs to trigger any drastic responses if we understand the study, the motive for it, the scientific process and the remaining need for us to find better solutions for this problem.

So I wrote this post, asked for and received feedback from 4 different kinds of experts all of whom I hold in very high regard. I have not written it because I think my opinion is more important than others, but because (i) my name is on the paper, (ii) I know the study well, (iii) I was instrumental (with others) in getting money to run it, (iv) I stand by it as a piece of good science and (v) I accept that I have played a significant role in the ‘explaining pain story’ and many out there are feeling they ‘deserve an explanation from Lorimer.’

My views (which do not necessarily reflect those of the rest of the authorship):

1. The single most important result in this paper is this:

“Two 1-hour sessions of pain science education were no more effective than a placebo intervention for improving pain at 3 months, 6 months, or 12 months after the onset of acute low back pain.”

This is a very important finding because it tells us that we will not gain any more pain relief by adding two sessions of specialised pain education to usual care in that group. We didn’t track what other care people had.  The lead author, Dr Adrian Traeger, summarised his response to the result on ABC Radio – ‘it is disappointing that we couldn’t shift this trajectory’. I share Adrian’s disappointment here. I thought we might – my clinical experience and our audit data strongly suggested it was a good bet.  But alas I was wrong – we clearly haven’t found the perfect treatment for back pain yet. We clearly need to check ourselves here and knuckle down for a new direction.

One might respond by saying ‘oh but SOME of them would have done really well and it is just a case of discovering what works for whom.’ But to me this seems a high risk position because if some do really well then some must do really badly too and our first commitment needs to be to ‘do no harm’. It also seems to be a reflex response, a bit cliché, and we can recognise it in the dying cries of every failed therapy to date.  We need to be open to the possibility that Pain Ed can do harm – I know I have done harm by inadvertently giving messages such as ‘your pain is not real, it is in your head, I don’t believe you and your suffering’. This reality – and I can clearly remember several patients who got this message – distresses me just because of how strongly it contrasts with what I actually believe – ‘your pain is totally real, it is in your body, I completely believe you and I honour your suffering’.  This harm has resulted from clumsy delivery, me being off my game or not understanding the science, or not understanding the person in front of me (or both!). I remain of the view that if people in pain actually understand pain better they will be better off for it. This study is a powerful trigger for me to accept how far we are from doing this well.

2. We need to recognise the design of the study and the limitations of the conclusion.

All participants in the study were within 6 weeks, and most within 2 weeks, of the onset of a back pain episode. They were considered medium to high risk of poor recovery via our MyBack tool, and had visited primary care; most participants in both groups received physiotherapy as part of their wider care (no difference here between groups – this was NOT a trial of physiotherapy); the trial did not control other treatment in any way but it did promote guideline based care in both groups (although we don’t know if people got guideline care); the control treatment controlled for time with a caring clinician and arguably added ‘telling your story’ – a component not as present in the pain education group. This is why the conclusion is as I have outlined above. I don’t generalise the result to other more comprehensive education packages or journeys, nor to other clinical populations or settings – although the evidence for education in general is not overly compelling. I can’t yet conclude whether or not ‘changing pain biology knowledge changes pain in people with acute back pain’.

3. Changing self-reported pain attitudes and catastrophising does not lead to less pain later.

This is perhaps a challenging discovery. I would have predicted that these two things would be related.  We have previously shown that pain knowledge doesn’t lead to pain reduction through the catastrophising pathway, so it is not totally surprising, but my understanding of pain biology is that if one truly thinks nothing is seriously wrong (the Pain Ed group reported being more convinced of this), then it should hurt less – they should be less protected by their own protective system. We have started exploring this experimentally and it does appear that people can answer questionnaires in one way but psychophysiology tests don’t align with their responses.  That result might be revealing a response bias in reporting, although JP Caneiro’s lovely study on implicit associations and fear show how tough it will be to elucidate this stuff.

One thing we need to do now is to dig out what we can on whether people in either group actually learnt about pain biology. We are planning to investigate whether changing pain knowledge in the first week relates to outcomes – but that is a planned analysis we haven’t got around to yet. It would have been good to get conceptual change data throughout the study, but the burden of testing on participants was already high. Next time perhaps.

Please go here to read part two

About Lorimer Moseley

Lorimer Moseley Body In MindLorimer is Foundation Chair in Physiotherapy and Professor of Clinical Neurosciences at the University of South Australia, and Senior Principal Research Fellow at Neuroscience Research Australia. He has published over 300 scholarly works. His H-index is 71. He leads the Body in Mind Research Group, which investigates the role of the brain and mind in chronic pain.

Reference

Traeger AC, Lee H, Hübscher M, et al. Effect of Intensive Patient Education vs Placebo Patient Education on Outcomes in Patients With Acute Low Back Pain. A Randomized Clinical TrialJAMA Neurol. Published online November 05, 2018. doi:10.1001/jamaneurol.2018.3376