This blog is a reflection on the recent Preventing Overdiagnosis Conference 2019 in Sydney, Australia. This is a concept far too complex to fit into any publically consumable blog, so for brevity and background, I recommend you read all of Lisa Schwartz and Steve Woloshin’s work or Ray Moynihan’s work. Some selected work is (there are probably far better examples) here, here and here.
The overdiagnosis concept can apply to all of medicine, but it may be most well known in the fields of cancer, cardiovascular and diabetes. I will focus on the musculoskeletal application of this concept. I think it’s important to zero in on this area amongst the broader ‘too much medicine’ concept because the musculoskeletal problem dwarfs the others mentioned. Chronic pain is costing more to the Australian Society than cardiovascular disease and diabetes combined (Ref). It is literally crippling our society. Musculoskeletal problems represent the majority of chronic pain conditions, and low back pain represent the majority of musculoskeletal problems – for this reason I will use these terms interchangeably throughout. If the medical system has become unruly in these other areas, then it is a runaway train when it comes to musculoskeletal medicine. When pain is concerned, ‘too much medicine’ is a train we no longer have control over, it is filled with zombie patients and practitioners and the best we can muster is a few rocks thrown at the track.
Overdiagnosis in musculoskeletal medicine
Overdiagnosis has been defined as,
“Making people patients unnecessarily, by identifying problems that were never going to cause harm or by medicalising ordinary life experience through expanded definitions of disease.” Broderson et al 2018.
Unless you have been hiding under a rock, then you will be well aware of the significant problem that this represents in musculoskeletal medicine. The real problem, in my opinion, is that these labels can be applied by just about anyone who claims to treat pain. And in the current landscape, this can be anyone from your local GP, your naturopath to the global conglomerate whose advert you just saw on TV. Diagnosis is not reserved to the small minority with imaging or prescribing rights; it is a fluid, uncertain process which has far too many fingers in the pie. So uncertain, in fact, that 95% of all low back pain cases are given the moniker of ‘non-specific low back pain’, meaning our diagnostic process has been unable to find anything specific causing pain. If you know anything about the science of pain, you’ll understand how utterly nonsensical the concept of ‘finding pain’ really is. Although we find a lot of other things, it doesn’t seem to correspond to treating someone’s pain. With all our fancy imaging modalities we seem to be unable to find this mythical beast.
And it’s not like we haven’t tried. There is a large body of work demonstrating the rate of imaging is increasing across primary care (Ref, Ref, Ref). This is in spite of a very clear message that routine imaging is not recommended by all guidelines of spinal care (Ref). When imaging is ordered for spinal pain, without the suspicion of red flag pathology, we call this ‘inappropriate imaging’. A glutton of data was presented during the conference by fantastic scientists demonstrating the ‘inappropriate imaging’ rate remains fairly constant, while the overall imaging rate is increasing (mostly unpublished work from Adrian Traeger, Sweekriti Sharma, Romi Hass from the Institute of Musculoskeletal Health, Sydney). Which means this increasing rate of imaging reflects an increasing rate of suspected red flag pathology. This problem is perplexing and raises a few questions. Does this increase in imaging really reflect an increase in suspected red flag pathology? Is this a red herring? Are clinicians lying or billing incorrectly? Or is it just hard to know what a clinician deems appropriate in the complex melee that is the clinical encounter? Lastly, and probably most accurately, does this confusing conclusion reflect just how complicated the diagnostic paradigm is in low back pain?
The cost of spinal imaging is small compared to the overall burden of low back pain. ‘Inappropriate imaging’ costs our Australian government something in the region of $23 million per year (Ref). This information is freely available from medicarestatistics.humanservices.gov.au. The overall burden of low back pain of around $9 billion; that’s right imaging accounts for less than 1% (Ref). This begs the question, is imaging the real red herring of overdiagnosis? Another way to look at this may be to understand the downstream effects. In other words, does it affect the way people with low back pain recover?
Surprisingly, the argument could be made that it doesn’t. In one large cohort of over 5000 non specific low back pain patients, imaging did not meaningfully alter outcome (Ref). In another randomised control trial, from the UK, consisting of 782 non-specific low back pain patients there was no difference found in clinical outcome with early imaging (Ref). What I don’t think this does is refute all clinical practice guidelines and puts the scientific consensus in doubt, rather it highlights the complexity of the issue. While imaging may currently prove to be a confusing picture, it alludes to a far more pervasive and far reaching aspect of the medical system’s overdiagnosis. Imaging might just be the tip of the iceberg – the first carriage in the runaway train that is the medical system. There are many ways to ‘create patients’ and label someone pathological, and maybe imaging is merely a tool kept for those that can wield it.
Words can harm and it’s the process of labelling, not imaging, that may be the bigger issue in diagnosis. In some lovely (unpublished) work by Mary O’Keefe presented at the conference, this concept has been explored. She has shown that when people with and without low back pain are exposed simply to different sounding words to describe low back pain, this has a profound impact on the perception of how serious it is and what treatment they’ll likely need. These labels were split into two ‘kinds’ and these were randomised amongst all people, she was able to test this in a novel way with a large sample. In a nice representation of the problem, she called these serious labels ‘biomedical labels’. These biomedical labels come from a system whose reason d’etre is to fit people into boxes in order to apply the appropriate treatment. This biomedical system involves all manner of professionals and we are all culpable in labelling patients in our own scary language. These labels lead to overtreatment and disability (Ref). This is the runaway train we need to figure out how to stop; our patients deserve it.
So while imaging may be the ‘above the line’ way to label patients, it still represents a fairly small portion of this runaway train. The rest of the medical system takes up the slack in producing disabled patients with consistent and unabashed use of scary labels. This ‘below the line’ behaviour mames people and we have only just begun to explore it, let alone think of ways to stop it. We’ve only explored a small portion of this problem, the first two carriages of the train. We still have the rest of the train to explore in later instalments. We will also explore why the people on the train really matter and why the rocks we’ve thrown at the tracks haven’t worked. Stay tuned.