Evidence-Based Physiotherapy: A Crisis in Movement

Being at the tail-end of a PhD in Evidence-Based Medicine, I recently re-read Trisha Greenhalgh et als’ BMJ Paper Evidence based medicine: a movement in crisis (see what I did there?) and now provide a plea for Physiotherapists / Physical Therapists the World over.

We are part of a wonderful profession, and also part of a fast changing world. It seems a good time now to reflect and act upon the past 20 years of growing evidence and information. These are some random reflections on Greenhalgh et als’ paper with Physiotherapy in mind.

Physiotherapists, please read and understand published data, but realise that this data is only meaningful when positioned within the narratives and socio-cultural contexts of our patients and our own experiences. Allow data – if sufficient – to free yourself from traditions and habits. Don’t be swayed by preposterous gadgetry and pretty colours but always look towards the data to drive positive ways of developing your practice. Stop handing out leaflets.

Human observations are prone to biases of perception and memory. Robust studies are designed to reduce such biases. Human observational biases can be easily controlled for by intellect. Most trials fail to control for biases sufficiently. Human observational biases are still evident though, for example the perception biases seen when interpreting the results of a trial. Treat real-life experience and outputs from studies as equally valid sources of evidence, which can both be highly fallible.

Stop inventing complex and unnecessary classification and diagnostic systems. They are not needed. Sub-classification is important, so pay attention to high quality studies which allow us to learn which interventions suit which patients. But the best systems are the simplest. Be aware though that the best sub-classification systems will also eventually sub-class down to N=1. At this point, population study derived data start to lose relevance. Evidence for patient management for the N=1 (i.e. your patient) needs to come from the source (i.e. your patient).

Touch people who need touching, this is therapy. Don’t touch people who don’t need touching, this is battery. Talk with people who need talking with, this is therapy. Judge when this becomes meaningless. Educate your patient by all means, but also let them educate you.

Pain science is undoubtedly important in evidence-based pain management. Pain scientists have reminded us that we have brains. That’s good. Heed pain science data, but stop fawning over pain scientists. They are not Gods. We no longer need ‘institutes’ and ‘organisations’ of pain science. If the data is good enough, it will speak for itself. Don’t fall into the trap of moving from ‘clinical guru worship’ to ‘research guru worship’. There are no gurus. Don’t be drawn-in by general theories of the world, e.g. pain, which are underpinned by fragile evidence, but do understand the potential ways forward such evidence might point. If you are a disciple of such trends, stop posting random quotes from random ‘pain’ therapists as if this were some sort of confirmatory proof of theory. It’s not. The easiest thing is to stop being a disciple, and start to think for yourself. A bit like a professional would. Ignoring biological aspects of our patients’ complaints is evidence-based silliness. Calls to abandon a biomedical model is evidence-based moronicy. And downright dangerous. Psycho-social dimensions are of critical importance to our reasoning and management. So is differentiating non-specific back pain from aortic aneurysm.

As a science, let us learn from other sciences. Experimental physics provide excellent data describing the Universe, but is reserved in making inferences to future events. Theoretical physics uses this data to better understand the world and consider ways to move forward. Where are our theorists?

As a human-centred profession, let us learn from the humanities. The idea of causation on which all physiotherapy research is based is 266 years old and philosophically and sociologically un-sound. Why don’t we look at developing research methodologies based on enriched notions of causation? Throwing data onto a stressed-out workforce won’t make that workforce do evidence-based practice. It will just stress it further. Let’s look at ways in which change can occur in complex social structures.

If you must adhere to clinical guidelines, then by all means do so but bear-in-mind that guidelines are more often than not administrative and political tools, with any clinical component aggregated out to a meaningless level.

Physical activity and exercises are, surprise surprise, looking like the things that really matter in our game. Movement is everything. Most of the time it doesn’t really matter too much how that occurs, as long as it does occur. It might involve touch, it might not. Movement helps people contribute to society and it keeps the world going. It also delays the onset of things like death. However, Government health and wellbeing agendas are weak and meaningless. Allow your patient to set their own health agenda. We all need exercise, but we don’t all need to do 50 one-arm pull-ups on barbed-wire with baying wolves at our feet. Nor do we need to run through man-made pools of mud pretending we’re in the army. Our job should be focussed on using the best of the data to work with our patients in a search of a way to restore and rehabilitate meaningful movement whether they have had knee pain, back pain, a stroke, respiratory disease, or cancer.

When talking with patients, don’t use relative risk and probability data in your conversations. Even really clever people don’t understanding what these mean. Incorporate absolute risk into your reasoning, but judge when and to what extent it is useful to share with your patient.

If you are organising a conference, try and engage delegates better by having fewer, shorter presentations (say, 10 minutes) and allow more time for questions (say, 40 minutes). If you are a conference delegate, ask questions. Conferences are still a valid way of sharing data and thought, but this only works if there is a two-way communication channel. Evidence can only be made meaningful via discourse.

If you are a research funder, PLEASE STOP FUNDING RIDICULOUS RCTs. Fund the good ones, of course. But you are the only people in the whole world who can facilitate a better understanding of how people manage multiple sources of information in complex social situations. Can you please fund work into this. This is evidence-based practice.

If you are a journal editor, please facilitate the dissemination of thought and knowledge towards understanding the integration of population data into individual decision-making, rather than worrying about your impact factor.

If you are a student, listen, engage, challenge. However, do not start your first day at clinical work by saying to your senior “where’s your evidence?” This is an utterly negative, unconstructive and unintellectual strategy. Rather, search for the areas of practice which could be better developed, work with others to develop ways to address these limitations. In the meantime, learn the craft of listening and communicating with your patients. You are the profession’s most precious resource. You are our future. Please be careful with the information you receive.

Greenhalgh et als’ paper marks a pivotal landmark in the course of evidence-based medicine. As they highlight, there is a lot of groundwork still to do, but the emphasis should firmly be on collaboration between all stakeholders. One dimension of Sackett’s original idea of EBM seems to have got lost over the last 20 years – the patient. Let Physiotherapy support the call for a campaign for real evidence.



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48 responses to “Evidence-Based Physiotherapy: A Crisis in Movement

  1. nicely written and stated Roger!

    One question comes to mind, and it might be semantics, or that you are referring specifically to assessment systems rather than treatment, or possibly that the systems people are creating are so complex they are unintelligible, yet, with pain being a complex human experience, should we expect a simple system to be best?
    This may be purely my filter – a very smart woman who was both an academic, specializing in theoretical constructs and paradigmatic thinking, and a person in pain, was none too happy when she decided that I was trying to simplify some aspects of pain science, in order to make it easier to understand.

    • Great point Neil. I suppose I would say this is down to judgement and the level/nature of communication needed for individual patients. It still seems though that on a broad epidemiological level, relatively simple systems e.g. STarTBack, hold more value. Within all this, different levels of communication can occur. I’m not meaning to over-simplify complex systems, but even the most complex theoretical physics can be reduced to relatively understandable notions. It seems like a lot pf PTs and patients are confused and overwhelmed by the complexity of some of our assessment and management systems. I’m sure there’s a healthy middle-ground somewhere. Thanks for you comments and sharing.

  2. Francisco

    i agree, we need a a campaign for real evidence.

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  5. Marjan

    Nicely put Roger. For once I could engage in your arguments and fully support your passionate plea.

  6. Rex

    Awesome, awesome, awesome stuff. The only sentence I cannot agree with at this time is your comment about pain organizations and institutes. Here in the United States, we do need pain science centers and organizations.The understanding of pain science and how to practice based on science is improving but is light years away.

  7. Colette Ridehalgh

    My goodness Roger; I tend to not want to fawn over anybody’s words, but if I could have written what you have written in such a beautifully phrased and succinct way, I would have. Evidence is used as a piece of weaponary these days it seems to me, with one up-manship on who can quote the most references in one sentence wihtout having read more than the abstract! I love pain science even though I nearly always feel incredibly stupid and inferior, and am constantly asking how it directly affects patient care.
    Guru worshiping has been around forever, but I really have seen a shift ot worship from the manual based weekend course gurus to the pain scientists who do “really clever research”. Of course if you ever catch them between their rats and microscopes and ask them about how that glial cell activiation can help you address how to mange Mrs Smith with her chronic low back pain, then things get a bit sticky. Goodness, does that mean that as Physios we have to decipher the literature and see now we can use it, develop it, or just plainly dump it?
    A post grad student on placement was quite concerned because he couldn’t see how the research could tell him what to do with his patient. I find it quite scary that there is such strong message being propgated by some academics, clinicians, commisioners and above all politiicans that the evidence can drive down costs and dicate treatment and management strategies for all patients. All patients??? Are all patients the same??? Do they behave in the same way to all clinicians and all management strategies? I think not.
    Sorry Roger this has turned into a rant. Thanks for letting me get that off my chest. As you can see, I love what you have written, but I promise that I won’t name you as my new favourite guru! Right back to my narrow, quantitative research which will tell me all the answers…..!

    • Hi Colette, well, I can only applaud, support and empathise with your excellent comments! I think we are a really “interesting” time in the development of our science, and the way we choose to use/interpret EBP will dictate whether we survive as a profession or not, or at least in what way we might survive. Thank you for your beautiful rant! Roger PS – can you let me know when you have the answers!

  8. Hi Rex, thank you for your comment. I suppose the point I was trying to make is why “Pain Science” (PS) should be privileged, in a EBP context. Of course, other institutes representing other areas of practice exist, and these are, ironically, criticised by PS. So I could make the same point about others.

    However, generally, I think we are at a time in our scientific progression when discrete institutes are not need per se. So, there was a time when clinicians would benefit from say. The McKenzie Institute. But in an EBP world, this shouldn’t need to be the case. We have developed skills which allow us to understand and interpret data and data-summaries ourselves, and allow us to contextualise that data with our patients. So why do we need an authoritative institute?

    Specifically, it seems like PS institute behave somewhat differently to others. PS is an alluring patch of thought and data, but it seems like the ‘institutes’ built on this are presenting the notion as some sort of general theory, confirmed with data. And doing this in an aggressive way which stifles discourse and debate. The data on which PS is built is a long way from affirming some sort of general theory, and even further from refuting other theories of pain and disability.

    If there should be institutes at all, they should be developed around broad notions of reasoning, evidence, and practice, and serve to facilitate, not terminate, debate and progress.

    Very best wishes


  9. Lea

    Hi Roger,
    I really enjoyed reading that, thank you.
    I agree with your comment… ‘The idea of causation on which all physiotherapy research is based is 266 years old and philosophically and sociologically un-sound.’
    You talk about ‘developing methodologies based on enriched notions of causation’…could you expand a little further on this? What do you think this would look like practically? Can you direct me towards examples of this being done well?

    • Hi Lea, good to hear from you and hope you are well. Thanks for you comments. Well, things start to get a little complex at this point. Here is an example: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2753.2012.01908.x/abstract
      If you can’t get the full-text but would like it, let me know and I’ll email you it. The practicalities of this are still to be worked on, but as an example, simply using multiple coherent types of evidence to establish causation, rather than just comparative studies, would be a start. The paper linked here talks about causation as a ‘dispositional’ notion. What is meant by this is that things (say, interventions) aren’t necessarily going to cause an effect. They need a ‘mutual manifestation partner’ (e.g. the correct conditions in a patient) in order for any causation to occur. So, in shop-floor terms, rather than saying “RCTs show that this works”, we would say “RCTs indicate that this has properties which might cause a health change, but I need to understand how this relates to my patient before we can judge if it will work or not”. It is the matching of the patient with the intervention which will produce the health change. This is why understanding patients as individual, complex organisms, rather than as a unit which is part of a sub-group/population, is important. This is where we/I believe the EBM hierarchy of evidence fails. Best wishes, Roger

      • Lea

        Thanks for the swift, and nicely explained, response Roger! I’d be very interested in reading the full article if you don’t mind emailing it? Many thanks. Lea

  10. Hi Roger, thank you for sharing your thoughts. What is your definition of “pain science”?

    Evan Raftopoulos

  11. Roger, thank you for the thought provoking post. I agree with many of the insights as well as frustrations you elucidate as well as the insight that evidence based practice is not really being understood and subsequently utilized correctly. Much work to be done…

    Your post seems to inadvertently create a few false dichotomies:
    Utilizing Bio-Psycho-Social OR Biomedical/Biomechanical. Similar issues are present in the proper application of the BPS model. The BPS model is meant to FULLY incorporate the biomedical and biomechanical model (it’s part of the “bio” part), but recognizes the importance of psychological and social constructs. The BPS down right is the biomedical model expanded and broadened to assess more than just a person’s anatomy and physiology.

    Missing an aortic aneurysm is not a failure of the BPS model nor “pain science” per se, but rather a failure of the clinician to properly screen medical conditions and rule out occult medical conditions.

    Pain Science OR Biomedical. Similar thoughts here. The application and integration of the science of pain into the treatment of patients should never ignore biomedicine, red flags, or proper medical screening. It’s inherent, and should be assumed, that as a professional you are charged with proper screening, ruling out, and evaluation.

    As you mentioned, those researching pain and the subsequent studies illustrate to us just how darn complex the individualized, lived pain experience really is. And, how many factors affect “pain.” It’s more than brains, but helping us recognize that PT is not just from C1 down is quite important. Yet, instead of recognizing this complexity and working to integrate understanding into practice, as you recognized, we instead make up complex treatment paradigms, classification systems, and sub-groups of responders in ways that are likely not quite valid. PT as a profession also loves to attempt classification of clinical syndromes into made up nominal pain diagnoses. Impingement, patella femoral pain syndrome, and other clinical syndromes/diagnoses come to mind. As you mentioned I’m not sure these nominal diagnoses or at times complex diagnostic constructs help us any….

    Per usual, Jason Silvernail summarizes the issue with keen insight so I will link to this must read post: http://www.evidenceinmotion.com/about/blog/2008/05/ebp-deep-models/

    Some of my general thoughts on integrating evidence and research into practice

    We absolutely must learn from humanities, psychology, and other scientists.
    Other relevant posts

    Some discussion happening here: http://www.somasimple.com/forums/showthread.php?t=19074

    Thanks again for your honest, straight forward critiques of what we do and the importance of modeling the WHY.

  12. Hi All. and apologies for delay in replying to your great comments.

    First, Evan, re: definition of ‘Pain Science’. So, I was being a little flippant, and using the term as I commonly hear it thrown around these days. Of course, by definition, this should mean any scientific knowledge/activity related to the understanding of pain, in any dimension. But what I was wanting to mean was something like this:

    “”That body of scientific knowledge which de-emphasises a biological component to a person’s painful experience and prioritises education as an interventional strategy”

    There is an interesting discussion on Facebook if you go to Kyle’s link above.

    I know this isn’t THE definition of PS, but it seems to me that this sentence highlights the differentiating components of a modern approach to the management of people with (chronic) pain. I’d like to hang-on to this definition for the purpose of these discussions, but maybe it’s wrong to label it as ‘Pain Science’.

    Kyle, thanks again for your fantastic contribution to these discussions, and for linking to other great information resources. As you know, ultimately, I agree with you and most things in life! Again, the flippancy of my blog was to highlight some (perceived) concerns. And I am fully on-board with Jason’s comments about the biomedical straw man. Also, your thoughts resonant with me re: the BPS model, although I feel that the model is insufficient (some thoughts here: http://www.peh-med.com/content/pdf/1747-5341-8-11.pdf ) It does, however, seem to be the clinical interpretation of any model/body of science, rather than the science itself. Although I do feel that certain ‘institutes’ encourage this mis-interpretation.

    Mis-diagnosis is not a failure of the body of knowledge/model itself, but it’s mis-interpretation is where failure occurs. We have some case studies coming out soon, but in a nutshell, this is the conceptual thing that worries me: chronic pain patient, seen by n=x PTs; numerous biomed approaches = no help therefore has pain-ed (or pain-ed from the start as is increasingly common); but pain is actually related to serious pathology. Better reasoning and understanding of sub-classes of who is best fit for pain-ed will eventually emerge, but at the moment there seem s a pendular swing which is missing some diagnoses. The message of ‘nocioception =/= pain’ is a mis-leading chant. This isn’t the case in vascular/cardiac/visceral/cancer patients.

    We have been witness to cases whereby physios have been laughed at or even bullied if they try and interpret a chronic pain patient in anyway other than a ‘pain-ed / non-nocioceptive’ way. Again, as you say, this is not the failure of the science, but rather the users of the science, and for my penny’s worth, fueled by institutes who are supposed to be representing the science.

    Using the best of the evidence in a sound reasoning model is/has/and always will be the key to best practice. We all just have to keep sensitive to when this is and isn’t happening. Folk like you and Jason are key to this quality assurance!

    • Hi Roger, thank you for your response. I see what you are saying, but I think that your definition creates confusion and can be misleading. For example, I’m not sure that I understand what a biological component to a painful experience is and what not. What else is there that contributes to a pain experience other than biology? Also, what does prioritizing education mean? It can be interpreted as more time talking and less time doing things such as exercise or hands-on approaches. However, exercise and hands-on approaches are also great educational strategies. Nevertheless, I enjoyed reading your article and I tend to agree with most of the things that you mention.


      • Hi Evan, and thanks again for your thoughts and feedback. Always very informative. I was being mildly facetious, but trying to retain Engel’s BPS vernacular and distinction between dimensions of pain and health. So whilst I accept you comment

        “What else is there that contributes to a pain experience other than biology? ”

        I am thinking about the behavioral (psychological) and social components, as differentiated in BPS literature. If we are not happy with ‘de-emphasising’ the biological, then we could always say that recent advances in clinical pain science suggest ’emphasising the psychological and social dimensions’.

        Likewise re: ‘education’. I agree with you that many of our interventions hold some sort of educational component. So what I was really referring to is the type of verbally/visually-driven educational strategies in-line with the work of Moseley, Butler, O’Sullivan etc.

        Hope this makes my (no necessarily correct) position a little clearer!

        Best wishes


  13. There is a lot of credence to you and Prof Greenhalgh writings. I hesitate to use the word ‘truth’ given the complexities involved.
    As a profession, PTs and other AHPs will have to look to aggregating a lot of data that is routinely collected in clinical work so that very large datasets can be created and then the new age of data mining and statistical analysis can be employed to ascertain if we are having the impact that we feel are. This is one means of recreating the call for EBP.

  14. Hi Roger, thank you for clarifying your thoughts. I’m far from an expert on understanding how sociology and psychology fit the scientific paradigm and in the context of msk pain, so I have no idea if that’s “pain science” or just expert opinions. But that’s just me.

    This is one of my favorite articles: Pain Medicine and Its Models: Helping or Hindering?
    John L. Quintner, MB BS, FFPMANZCA,* Milton L. Cohen, MD, FFPMANZCA, David Buchanan, PhD, James D. Katz, MD, and Owen D. Williamson, MB BS, FFPMANZCA

    Click to access Pain%20Medicine%20and%20Its%20Models.pdf

    Quintner et al. question if this model has overcome the limitations of the biomedical model. I think their arguments are sound. What are your thoughts?

    About emphasizing verbally/visually-driven approaches, that seems to be a small part of the pain medicine literature, at least to my understanding.

    Thank you for this discussion,

    • Hi Evan,

      Thank you for that article. At first read, it appeals to how I think about the limits of the models we use, including of course the BPS model. I will read in more detail to understand the precise argument and alternatives.

      In general, I too am unsure of the ‘success’ of a BPS model. This is a paper which (implicitly) reflects this:

      Click to access 1747-5341-8-11.pdf

      Also, I agree with your comment about the magnitude and strength of evidence supporting the sort of educational strategies I have been referring to. There seems to be a increasingly evangelical spin of the true value of this evidence.

      Thanks once again for your contributions and knowledge.


  15. Hi Roger

    What a fantastic read. I have to hold my hand up and admit that I am a culprit of some of the things you mention – guru following, jumping on the psychosocial approach too much. However my clinical practice has changed so much from using social media and writing my own blog and reading blogs like yours, Adam Meakins and David Nicholls that have an opinion and an open mind to topics such as evidence based medicine and the next fad that we all jump upon. What we experience in clinical practice does not always meet the controlled conditions of RCTs, which is why I love working in clinical practice as you get a perspective of evidence based approaches. I have become much more aware of myself as a practitioner and really focused on critical thinking and reflective practice.

    Thanks for a critical and informative read!


  16. Hi Roger,
    Greatly appreciate this post, and in particular the interest in returning the therapist’s view to the individual person in front of them. How easy it is to view all instances of “medical epicondylitis” (or any other dysfunction) the same way! Same (or essentially the same) exercises, same manual therapy, etc! Also appreciate the interest in enriching the profession with attention to the humanities, and causation in particular.
    I just got access to the full text of your article and hope to work through it soon, but I have to take issue with – or at least seek clarification on – one item. You say, “the idea of causation on which all physiotherapy research is based is 266 years old and philosophically and sociologically un-sound.” I take it you are referring to Hume’s Inquiry Concerning Human Understanding (published 1748) with this? Aristotle’s notion of cause is I think much richer and truer to our experience than Hume’s excessively narrow formulation. The Scot seems to think there to be essentially only one cause, what Aristotle calls efficient cause. Have you spent any time considering how Aristotle’s fuller account can encompass the advantages of Hume’s formulation but within a broader, more true-to-experience formulation of causation?
    Thanks again for the thoughtful post.

  17. Reblogged this on myosportstherapy and commented:
    Always worth taking time out to read Roger Kerry’s thoughts

  18. britt smith

    I’m just piling on after re-reading this blog. You are spot-on with all aspects. PTs have to stop swinging from fad-to-fad and guru-to-guru. Movement matters most. Tim Flynn PT, PhD’s editorial in JOSPT, Move it and Move on, nicely summarizes the flow of care….don’t dwell on one aspect of care (e.g. manipulation), but view it opening the ‘window’ to the next phase of care, and patient independence. Focus on how best to meet the patient’s goals AND independence from this crazy medical system (USA). I like to tell patients from the get-go that if I’m effective, then I’m ‘biodegradable’, i.e. I will disappear into the landscape (in the west: ride off into the sunset) without a trace. Thank you for your leadership. Britt .

  19. Hi All, and thanks for you comments,

    Thanks for your comments Samantha.

    Paul, you are not alone! I’m sure we are all guilty of all things at some point. The difference is knowing when to move on. It’s so easy to get trapped in certain ideas / institutes. Reflection and reasoning will always get us out though.

    Hi Harrison, indeed ’tis the great Scot to whom I refer. I’m no expert on Aristotle by any stretch of the imagination, but certainly his ideas on causation would fit better to what we aspire to. The problem (challenge) is that if comparative studies / observation studies lead the way in establishing ‘what works’ (causation), then I think we are immediately caught in a Humean trap. That’s not to dismiss what such methods have to offer, it’s just a signal to re-analyse, after decades of trials, what is it we actually mean by causation? Is the sort of causation we want with our patient the sort which is established in a trial? Some big questions:)

    Thanks Britt, I’d be happy to ride off into the sunset with you. As long as we were heading for the bar! We could biodegrade over a couple of beers as we ponder some more questions:)

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  22. James

    The application of pop neuroscience to patients with ‘chronic’ musculoskeletal pain has resulted in other allied health disciplines making judgement on the management of these patients in a primary contact role where I work. So I witness patients entering a 12 week ‘pain’ program and listen to these disciplines ‘educate’ them on pain. Physios have lost the authority to a large extent. Its especially disenchanting when I cherry pick a patient into a musculoskeletal physio clinic and discover a peripheral / spinal driver of their pain that has been missed along the way. So before you commence a non relevant parrot like repetition of pain science in front of your patient, please perform a thorough and skilled musculoskeletal assessment and clear these drivers, otherwise you are costing the taxpayer and the patient. I know the pain consultants agree. Also think about the ramifications on our reputation as a profession. Well written Roger, please continue.

  23. excellent! seems very appropriate what the author said. Especially where you say Physical activity and exercises are, surprise surprise, looking like the Things That really matter in our game. Movement is everything.

  24. Pingback: Research into practice #physiotalk on Monday 28 June 2015 | physiotalk


    HI Rojer,Just discovered this website.Intersting read.I have gone through all this guruism and now thinking what am i really doing.
    Can you e-mail me the paper on:
    Causation and evidence-based practice: an ontological review

  26. “Human observational biases can be easily controlled for by intellect.”

    Is that true Roger?

    It would seem (to me) that many highly intelligent people of no small intellect have in the past made such errors – and is it not this very premise (among others) that Sackett sought to undo?

    Indeed once you assume that you can guard against bias by your intellect alone are you not in one of the most vulnerable places of all? I wonder if the argument be made that this statement an example of bias ;-)?


    • Hi Andrew, sorry, just seen your message.
      A premise of systematic research, as you know, is to reduce bias error, at least to a degree better than that found in human reasoning. This premise has almost been taken as read over the years, and it really needs some more thought. The argument is usually made by people who have half-read half of Kahneman.

      The sorts of judgment usually referred to are not really comparable for a start. Population research aims to reduce risk of bias related to a specific primary hypothesis and the chance of a false outcome related to a statistical average. This would indeed be difficult for a single human to achieve with a low error in judgment, and this seems to be the basis of the premise. To support this further, most of the data to support the ‘human bias’ argument (for EBM) comes from tests in experimental situations, with abstract problems, such as that above. These experiments have themselves been shown to artificially increase the degree of biases. Real-world tasks result in less judgement error, and humans have been shown to provide results comparable to probabilistic prediction models, when the task is real and meaningful, see Girgerenzer’s data, for example. Further, when random noise is reduced, and content knowledge is increased, human bias error is often insignificant. Reducing noise and increasing knowledge is what our education teaches us to do. Maybe I should have said “education” instead of “intellect”.
      However, I would say that when interpreting a patient narrative and cognitively organising a large body of continually evolving information in a multi-dimensional biopsychosocial framework, whilst engaging in non-authoritative communication with another human being in order to establish that person’s return to function is something that we can be intelligent and thoughtful of. Within this, from the data, biases will exist, but what would be the significance of these, and can they be moderated in a real-world context with the patient?
      In sum, I think (like many others, even from deep within the EBM movement), that the ‘human bias’ argument is a fallacy, and is a very poor rationale for supporting the use of population data into practice. There are better arguments for that.
      Sorry for being wordy, I took some of this from another blog. Thanks for engaging. Roger

  27. I am just going to keep this short… Thank you for a well written and Timely Blog

  28. Evan

    Thoroughly enjoyed your informative post!


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  31. Hi Roger,
    I’m clearly 2 years late reading this great post, but glad I bumped into it. Lots of interesting comments on pain science as one would expect, but I’m curious about your idea of a PT Theorist. What would you envision that looking like and what type of information would the output be? How would one go about doing that and who would the information be useful for?
    It’s an intriguing idea and curious that it exists in other areas, but not in PT.
    Thanks again for the thought provoking read.

    • Hi Cody
      Thanks for engaging. I’m not sure entirely what this would look like. In my mind, we seem to have gone from clinical randomness to full-on science. Of course there are theories alluded to along the way (e.g. older theories of practice, theories which are tested by our science), but it all seems professionally unstructured. I don’t think the vision is something as explicit as in Physics, but there is no reason why it couldn’t be. We seem to treat theory as second rate, which is a-scientific. Whereas science would say “lets see how well the data fits the theory”, we say “well that SR/RCT proves that’s wrong”. Theory, practice, and science should inform each other and should have a fluid relationship. I’m not sure that’s how we behave. I remember something I wrote years ago partially related to this (link below). Anyway, the aim of that comment was to get some thought going, so glad you have asked this.



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