It’s time for patients and clinicians to have frank discussions about what diagnostic imaging scans can do for low back pain, and what they cannot, according to research published recently in BMJ Open.
Three of the authors, Adrian Traeger, Swee Sharma and Chris Maher, all from the Institute for Musculoskeletal Health at the University of Sydney and Sydney Local Health District, summarise their work below.
It is published as part of the TOO MUCH of a Good Thing series, which is investigating how to reduce overdiagnosis and overtreatment in Australia and globally, and is published as a collaboration between Wiser Healthcare and Croakey.
Adrian Traeger, Swee Sharma and Chris Maher write:
Many Australians will have experienced low back pain. When it strikes, back pain can be surprising, disabling, and almost always worrying. For some, the pain subsides quickly and so too does the worry. With the help of little more than a heat pack, they can return to normal activity within days or weeks. For others, the pain persists much longer, upturns what was once a happy and healthy life, and triggers a long and unsatisfying search for answers.
Finding out what is wrong
Regardless of how long the pain has been there, people with low back pain want to know what is wrong.( Clinicians can diagnose most conditions that cause low back pain by asking specific questions and performing an examination (e.g. they may press your spine, ask you to bend in different directions, or lift your leg into the air). If a clinician suspects a serious cause of low back pain, they might send you for a diagnostic imaging scan (x-Ray, CT or MRI).
The problem with too much imaging
There is increasing evidence that it is not just those who clinicians suspect have a serious condition that are sent for imaging.
One recent study of over nine million consultations found that clinicians referred around one quarter of people with low back pain for a diagnostic imaging scan. If we expect that around 1 per cent of patients who see a GP have a condition that needs urgent imaging, at least on the surface, these numbers seem too high. Some concerned clinicians, the back pain research community, and more recently international initiatives such as Choosing Wisely®, have held lumbar imaging for low back pain firmly in their sights as a “test to question”.
One reason for the concern about too much imaging is the risk for a problem called overdiagnosis. Overdiagnosis occurs when a person receives a diagnosis that brings them no benefit or causes harm. That is, a diagnosis that people would be better off not knowing.
When it comes to diagnostic imaging for low back pain, imaging reports often show age-related changes such as “degenerative disease” “disc bulges” and “arthritis” that are very common in people without low back pain. Such findings increase worry and may lead people to pursue interventions to try to fix these problems; but they may not be the cause of their pain. This is an example of overdiagnosis.
What did we do in this new research?
We wanted to understand how clinicians and patients viewed – in their own words – the role of imaging tests for low back pain. Understanding these views could help uncover reasons why imaging happens too often. We compiled all of the available studies that had interviewed patients and clinicians about diagnostic imaging for low back pain.
We located 69 studies from across Europe, Australia, North America, and Asia, which included 1747 participants. This was the first time such a large volume of diverse diagnostic imaging studies had been combined to understand the problem of too much imaging.
What did we find?
Although many participants had accurate views of the role of diagnostic imaging, we were surprised to find several misconceptions expressed in interviews with patients and clinicians. We could organise some of these views into key facts and key misconceptions about what diagnostic imaging can and cannot do.
- Diagnostic imaging can locate the source of typical low back pain FALSE
The most commonly expressed view by patients and clinicians was that imaging is useful to locate the source of low back pain. This surprised us because we know that for the majority (around 90-95 per cent)of people) who have typical or ‘garden variety’ low back pain–sometimes referred to as “non-specific” low back pain – accurately locating the source of the pain is not currently possible. In other words, even the most sophisticated diagnostic imaging scan cannot tell a clinician with any certainty whether someone’s back pain is due to a joint, muscle, or disc problem.
- Diagnostic imaging can make patients happier TRUE
Our review found many patients associated a referral for imaging with better clinical care. In other studies where imaging is provided to one group of patients with low back pain, and withheld from another, there was evidence that a referral for imaging could increase satisfaction with the consultation.
- Diagnostic imaging can only harm you via exposure to radiation FALSE
Participants in our review rarely mentioned potential harms of unnecessary imaging. When they did, understanding of potential harms appeared to be limited to exposure to radiation. There are several others. Documented harms of imaging include imaging findings that increase worry, worsen recovery, and risk use of misdirected, invasive interventions such as injections or surgery.
- Diagnostic imaging can rule out serious problems with the spine e.g. cancer TRUE
A key reason both patients and clinicians valued imaging was to rule serious problems such as cancer, fracture, or infection. Tests such as MRI do form a critical part of the diagnosis of these problems.
- Diagnostic imaging can provide evidence that persistent pain is real FALSE
In our review patients expressed a desire for imaging results that would demonstrate to friends and family that their ‘invisible’ pain was real. Unfortunately, it is not possible using current spinal imaging techniques to determine whether a person is in pain or not.
- Diagnostic imaging can validate the pain experience TRUE
Many patients expressed relief when their imaging findings showed what appeared to be a damaged spine. Previous research has also shown that imaging results which appear to ‘fit’ with a patient’s symptoms could make them feel as though their pain experience was validated.
Why do these findings matter?
Diagnostic imaging scans are an essential test for only a small number of people who experience low back pain. Although they can rule out serious problems, so too can skilled clinical questioning with less hassle for the patient and less potential for harm.
Scans cannot provide visual evidence of pain; but patients clearly want this. Clinicians need tools to provide reassurance and validation for an experience that in most cases cannot be adequately explained by even the best medical tests.
Our findings suggest it is time for patients and clinicians to have frank discussions about what diagnostic imaging scans can do for low back pain, and what they cannot.
The series investigates how to reduce overdiagnosis and overtreatment in Australia and globally. The articles are also available for republication by public interest organisations, upon request.