Wasteful scans in back pain
Researchers investigated the effectiveness of magnetic resonance imaging in the care of patients with back problems like sciatica and lumbar-disk herniation.
Norman Swan: But let's get back to that question about the value or not in getting your sore back x-rayed, CT scanned or imaged using magnetic resonance. It's a huge issue involving tens if not hundreds of millions of wasted Australian tax payer dollars each year.
Findings in a paper in a recent New England Journal of Medicine have yet again doubted whether MRI scans tell you much that's useful at all when you've got low back pain or sciatica.
Someone who's had a long interest in spinal x-rays and MRI scans is Richard Deyo, who's Professor of Family and Internal Medicine at Oregon Health and Science University in Portland. Rick wrote the editorial in the New England Journal which accompanied this study. He argues that the psychological impact of seeing an image is much larger than, say, the result of a blood test.
Richard Deyo: Yes, I think so, I think visual evidence is more compelling for many of us than simply hearing a number or getting a lab result, and seeing is believing.
Norman Swan: What's the problem, in your view, with spinal imaging?
Richard Deyo: Well, the problem is that spinal imaging shows so many things that it's often abnormal, even in people who have no back pain at all, and that creates an opportunity for both doctors and patients to be misled into thinking that there is something important causing the pain when it may actually be something that most people have without any pain.
Norman Swan: There was a study you've quoted of people with no back pain at all where they did spinal x-rays or MRIs.
Richard Deyo: Yes, that's exactly right, there have been several studies that actually show that normal people, people who have never had any back pain or sciatica, often have herniated discs, they often have degenerated discs and bulging discs and things that looked just awful but that don't cause them any problem at all.
Norman Swan: You also quoted a remarkable study where people were randomised…they got their MRI, but they were randomised to receiving their results or not.
Richard Deyo: Yes, that's right. In this study MRI scans were done on a large group of patients, but only half were given their results, and it turned out that the patients who did not get the results actually reported better improvements when they were followed up than the patients who received their results, suggesting that simply getting the results of an MRI scan may be sufficiently alarming that people feel less healthy.
Norman Swan: And what's the hit rate on MRI scans of actually finding something that actually means something? Because doctors are fearful of missing something like a tumour in the spine.
Richard Deyo: Yes, that's right, doctors are very concerned, and rightfully so, about missing something like a tumour in the spine. The good news is that a careful office medical history and examination of the patient can usually make that problem very unlikely, and it usually doesn't require fancy imaging tests. In situations where the concern is greater, it's often true that a plain x-ray and a simple blood test, which are far less expensive, may be just as good a screening test as doing a more expensive MRI scan. The office exam helps to identify worrisome things like a fever or a history of cancer that would drive you to doing an MRI scan sooner rather than later.
Norman Swan: And the rates in the United States of MRI scans of the back are highest in areas where there are higher surgical rates.
Richard Deyo: Yes, that's right. It seems to be true that where more MRI scans are done there also appears to be more surgery, and we've done some studies that suggest that even with that higher surgery rate those patients don't necessarily have any better results than the patients who didn't get those MRI scans.
Norman Swan: So who's driving what, because surgeons will do MRIs to plan their surgery, and in fact you and others argue that is really one of the few reasons for doing an MRI of the spine. So isn't it just the surgeons doing the MRIs for surgical reasons?
Richard Deyo: No. In this particular study that looked at geographic variations, even after subtracting the MRI scans that were done specifically for surgery, it looked like the areas that did more MRI scans also did more surgery. So you're right, doing the MRI scan is valuable for planning surgery, but usually that should be in a patient who already has the signs and symptoms that the doctor sees on the office examinations that would suggest that surgery may be a useful treatment.
Norman Swan: We talked about people with no back pain and they could have quite horrible looking backs with no back pain at all. When you do have back pain and you find scarring or a bulged disc or whatever, how closely does the findings on MRI correlate with the back pain itself?
Richard Deyo: Well, the correlation between the MRI findings and the back pain is very poor in fact. That's demonstrated by the fact that we see so many abnormalities in people who have no back pain at all, and we often have studies that suggest that patients that have really bad looking scans are actually not complaining of pain at all. So the correlation is not nearly as good as we'd like it to be, and that's the reason why the office examination is so important.
Norman Swan: And just before we go any further in this conversation, what we are saying about MRI applies to CT scanning of the back as well.
Richard Deyo: Yes, that's absolutely right. CT scanning has all the same problems, and in fact if you do CT scans in normal people you find almost exactly the same rate of abnormal discs and degenerating discs.
Norman Swan: And this study that was recently published in the New England Journal of Medicine was following up people who'd had either back surgery or no back surgery for their back pain.
Richard Deyo: Yes, this particular study which came from the Netherlands was a clinical trial comparing surgical versus non-surgical treatment for patients that had a herniated disc with sciatica, the pain that radiates down the leg. This was a one-year follow-up, so the MRI scan was being done a year after patients entered the study. And the researchers found that whether patients had further signs of a herniated disc or scarring from the previous surgery didn't seem to correlate at all with whether they were still having pain a year after they entered the study.
Norman Swan: Of course it still begs the question; what is causing the back pain?
Richard Deyo: It does beg the question of what is causing the back pain, and this is still a big conundrum for doctors who are trying to interpret these scans and trying to figure out whether a finding on the scan is actually relevant or not. So the clinical findings become very important. That is, we'd like to see signs and symptoms in the office that correlate well with what shows up on the MRI scan. And it can sometimes be the case that something that looks alarming on the scan may not actually be causing inflammation of the nerve root, that is the swelling and the redness that often comes along with a herniated disc, if there is none of the swelling and the redness there may be no pain. So just seeing the MRI image alone isn't really enough.
Norman Swan: So what's the story for consumers? You've got a bad back, you go to see your doctor, people have an expectation sometimes, like they often do for antibiotics for a sore throat, they have an expectation that you've got a bad back, you're going to have to have an x-ray or CT, maybe an MRI if you can afford it. And what's the message for doctors who face these demands from patients and are also in the back of their mind fearful that they might get sued if this is the one in 1,000 patients who might actually have something in their back that needs attention?
Richard Deyo: I think the message for patients, who often want to have these tests done, the message is that these tests may not actually explain the cause of their pain and may result in misleading information. One should be cautious about requesting these tests, and if a doctor does a careful examination in the office and feels the test is unnecessary, you can believe him.
For the doctors I think the message is that it's actually possible to screen pretty carefully for the serious causes of back pain on a good office examination, and we should be limiting the imaging tests to patients who have signs and symptoms that would lead you to believe they might have an underlying spinal infection or a tumour or a serious neurological problem that really would demand a further investigation.
Norman Swan: And what are the red flags that would lead you to that assumption?
Richard Deyo: The red flags that would lead a doctor to that conclusion would be a history of things like injection drug use or a history of cancer, an unexplained fever, unexplained weight loss, those findings, along with a new onset of back pain, would certainly cause concern and would prompt an early evaluation with imaging in most cases.
Norman Swan: And what about…the incentives in the United States are the same as the incentives here, at least until you've got your healthcare reforms and accountable care organisations, but the incentives are basically you have these large corporate radiology practices who make their money by doing these scans and you have the payers who gnash their teeth and know that they're spending hundreds of millions of dollars unnecessarily. What might be the loop back to doctors? Because some people have tried on the reports giving information or when doctors order tests giving them feedback about whether or not they are worth doing.
Richard Deyo: Yes, there have been some studies suggesting that if the radiologist who reads the MRI scan would simply add a note about how common these findings are in normal people, it might cause less alarm on the part of both the primary care doctor and the patient and might help them to interpret the results in a more cautious way. It appears that when this has been tested in some preliminary studies that it may result in less ordering of additional tests, less ordering of invasive treatments and so forth.
Norman Swan: And with healthcare reform in the United States and Oregon where you are, it's one of the most aggressive if not the most aggressive state in the United States at the moment in terms of trying to get new models of care and driving costs down, what are your accountable care organisations doing about this sort of unnecessary expenditure?
Richard Deyo: Well, the state has promulgated development of a new set of guidelines that have been distributed to physicians. They've also tried to develop some new educational materials that are available online for patients with back pain through a government website, and the financial incentives are beginning to change in a way that will perhaps make it less lucrative and less desirable to do unnecessary imaging and that may drive much more selective use of these tests so that they are reserved for situations where they really are going to help.
Norman Swan: And these are, what you're referring to, are bundled payments to healthcare providers rather than fee for service.
Richard Deyo: Yes, that's exactly right, they are bundled payments and getting closer to a situation where doctors are paid a fixed fee for the care of their patients and have to live within that fee for a panel of patients.
Norman Swan: Rick Deyo, who's Professor of Family and Internal Medicine at Oregon Health and Science University in Portland.
El Barzouhi A et al. Magnetic Resonance Imaging in Follow-up Assessment of Sciatica. New England Journal of Medicine 2013;368;11: 999-1007
Richard A Deyo Real Help and Red Herrings in Spinal imaging. (Editorial) New England Journal of Medicine 2013;368;11:1056-1058
- Professor Richard Deyo
- Professor of Family Medicine and Internal Medicine
Oregon Health and Science University
- Dr Norman Swan
- Brigitte Seega