The Problem With MRIs for Low Back Pain
Like all primary care physicians, Danielle Ofri sees a lot of aching backs. Low back pain is one of the top five reasons people visit the doctor, and based on extensive experience, Ofri knows how the conversations will go. Patients want relief from miserable pain, so they want an imaging study. “I want to see what’s going on — that’s what they say,” says Ofri, who treats patients at Bellevue Hospital in Manhattan.
The easy thing to do is order a scan and send them home to wait for the results. The right thing to do, in the vast majority of cases, is to deliver the bad news: They need to wait for the pain to subside on its own, which may mean a few weeks of agony. In the meantime, if possible, it’s best to stay active and limit bed rest. An over-the-counter pain reliever might help. Unless certain symptoms point to a more serious problem, the physician shouldn’t order any imaging within the first six weeks of pain. On this last point, medical guidelines are remarkably clear and backed by studies demonstrating that routine imaging for low back pain does not improve one’s pain, function, or quality of life. The exams are not just a waste of time and money, physician groups say; unnecessary imaging may lead to problems that are much more serious than back pain.
And yet, between 1995 and 2015, magnetic resonance imaging (MRI) and other high-tech scans for low back pain increased by 50 percent, according to a new systematic review published in the British Journal of Sports Medicine. According to a related analysis, up to 35 percent of the scans were inappropriate. Medical societies have launched campaigns to convince physicians and patients to forgo the unnecessary images, but to little avail.
It’s a symptom of a well-diagnosed problem: the overuse of medical services. Unnecessary imaging isn’t confined to just low back pain. Americans spend more than $100 billion on various types of diagnostic imaging each year, much of which is unnecessary and potentially even harmful. F. Todd Wetzel, past president of the North American Spine Society, identifies the problem as “the technological tail wagging the medical dog.” After MRI and computed tomography (CT) emerged in the 1970s, many physicians started routinely using scans to make a diagnosis for low back pain, rather than using them the way they’re intended to be used: to confirm or refute an uncertain diagnosis.
Overuse of diagnostic imaging was crystal clear a decade ago, but medical practice changes slowly. Conventional wisdom suggests that, on average, it takes 17 years for new medical knowledge to be incorporated into practice. Arthur Hong, an economist and primary care physician at UT Southwestern Medical Center in Dallas, has studied inappropriate imaging for low back pain. He says public health campaigns — think about smoking cessation, for example — move slowly. “It’s taking a long time and we're not there yet, but it’s a worthy effort,” he says. “We’ve got to keep trying.”
Low back pain is a major health care headache in part because it’s so common. At least 60 percent of U.S. adults will experience it during their life and more than 30 percent report experiencing low back pain the preceding three months. In the U.S., an estimated 264 million work days are lost every year because of back pain.
Cheryl Clay, a recently retired office worker in Springfield, Missouri, hurt herself when she picked up a case of soda 40 years ago and she has suffered low back pain on and off ever since. “It’s a throbbing, aching pain and when it flares up, it’s a consistent ache,” she says. “It’s like it is locked — like my back is trying to bend but it is locked halfway.”
Clay is hardly alone; recurring back pain episodes are common. Not surprisingly, many sufferers end up in a doctor’s office. According to medical guidelines, the physician should examine them for red flags that suggest infection, fracture, or another urgent problem. If none are seen, the cause of the patient’s pain is most likely muscle strain, herniated disc, or degenerative disc disease, a term that describes the signs of wear and tear on the spinal discs as they age, says Wetzel, who is chief of orthopedics at Bassett Medical Center in Cooperstown, New York.
“Ninety percent of patients with low back pain will respond to things like medication and goal-directed physical therapy, and they do not need imaging at all,” Wetzel says.
Physicians say there are good reasons to avoid imaging. Though X-rays are inexpensive, they zap a patient with radiation, which may raise one’s risk of cancer. (High doses of X-rays are known to cause cancer in humans, but the carcinogenic effect of exposure to radiation at the low doses associated with medical imaging is not well supported; still, the average radiation from a spinal X-ray is 75 times higher than that from a chest X-ray, leading medical guidelines to caution against unnecessary exposure.) CT scans also use radiation and are more expensive.
But the biggest problem, say physician groups, is the MRI. While this technology doesn’t use radiation, it is expensive and can actually provide too much information. David C. Levin, a radiologist at Thomas Jefferson University Hospital in Philadelphia, explains: “If you took a whole bunch of people who had no symptoms and did MRIs of their low back, you'd find all kinds of disc herniations and protrusions and all sorts of other things that really aren't causing symptoms.” The majority of adults over 60, for example, have some disc degeneration — but it may not be the cause of low back pain.
MRIs frequently lead to surgery for benign abnormalities, says Wetzel, who has researched why back surgeries so often fail to alleviate symptoms. “The MRI provides so much information that oftentimes it's difficult to realize that much of it may be irrelevant to the problem that brought the patient to your doorstep,” he says.
MRIs of the lower spine also detect abnormalities on nearby organs. Adrenal glands, Levin says, are notorious for having cysts that, in the end, won’t cause any problems. But once a radiologist spots even a small mass on the adrenal gland, it has to be reported to the primary care doctor because it could be cancer.
That will likely lead to more tests which, in turn, may find more potential problems that may or may not be something that actually needs attention. And anything that leads to surgery puts the patient at additional risk. A recent study of so-called low-value hospital procedures found that spine surgeries for uncomplicated low back pain were associated with high rates of hospital-acquired complications, infections being the most common.
The researchers’ conclusion: use of low-value procedures “in patients who probably should not receive them is harming some of those patients.”
The idea that patients receive medical procedures that physicians consider unnecessary, wasteful or “low-value” may seem strange — unless you work in health care.
Nearly a decade ago, the Institute of Medicine (now the National Academy of Medicine) estimated that 30 percent of health care spending is wasted. Other estimates have ranged from 27 percent to more than 50 percent; an analysis published last year in Health Affairs said that “wasted spending now comfortably exceeds $1 trillion annually.”
That waste includes excessive administrative expenses (for medical documentation and billing, for example) and fraud, but every calculation includes a healthy dose of “unnecessary services.” The Health Affairs researchers estimated that roughly $241 billion in 2016 was wasted on overtreatment.
To chip away at that, the American Board of Internal Medicine Foundation launched the Choosing Wisely initiative in 2012 with the goal of reducing unnecessary medical tests and treatments. The idea is that each medical society identifies a list of the top five “overused” tests and treatments in its specialty and encourages its physicians to mend their ways. Items on the list are by no means verboten; rather, items on a society’s Choosing Wisely list deserve careful consideration rather than a quick decision.
Some 80 medical specialty societies have since called out more than 540 low-value tests and treatments. Imaging for low back pain might be the most popular target. Eight specialty societies — including two of the largest, the American College of Physicians and the American Academy of Family Physicians — have tagged imaging for low back pain as an overused service.
So far, the campaign has not been a rousing success. In the first two-and-a-half years after Choosing Wisely started, inappropriate imaging for back pain dropped just 4 percent, according to Hong’s research. He looked at imaging in the U.S., where Choosing Wisely got its start. The campaign has since spread to 20 countries around the world. Earlier this year, a research team reviewed 45 studies of low back imaging rates in North America, Europe, Australia, and New Zealand between 1995 and 2017. During that time, one in four patients who visited a primary care doctor complaining of back pain received imaging. For those who visited an emergency room, the numbers were one in three.
“The rate of complex imaging appears to have increased over 21 years despite guideline advice and education campaigns,” the researchers said.
Why does inappropriate imaging remain so common? Research points to a number of factors, including what is, for many physicians, a paradox. “It’s hard to be responsible for taking care of folks and then only tell them the things you’re not going to do for them,” says Hong.
Financial incentives can prompt physicians to provide unnecessary care, and physician ownership or investment in imaging facilities is associated with higher rates of imaging. But physicians working in the U.S. Department of Veterans Affairs (VA) system, which provides low- to no-cost health care to more than 9 million enrolled veterans and their families, do not have financial incentives for ordering wasteful images — and yet a nearly a third of the MRIs they ordered for low back pain in a single year were inappropriate. When that was discovered, a research team set out to figure out why these scans were being ordered. The researchers asked nearly 600 VA physicians, nurse practitioners, and physician assistants what they would do with a hypothetical 45-year-old woman — low back pain, no red-flag symptoms — who was asking for an MRI or a CT scan.
Only 3 percent thought the scan was a good idea and 77 percent said they would worry that imaging would lead to unnecessary tests or procedures. But clinical judgment wasn’t the only thing on their minds. More than half the clinicians thinking about the hypothetical patient feared that she would be upset if she did not receive imaging and that Choosing Wisely recommendations would not be persuasive. “Many patients don't feel as though they're getting an appropriate evaluation for back pain unless they have an MRI,” Wetzel says.
And more than a quarter worried they would be leaving themselves open to a malpractice claim if they didn’t order the test. “It’s easier to follow the path of least resistance,” Levin says. “Let the patient go get an MRI and then see what happens.”
Hong was a resident physician at Mayo Clinic several years ago when a radiologist came to see him complaining of low back pain. During the examination, he found no red flags, and the patient volunteered that he knew the imaging guidelines for the situation.
“But he felt so terrible, and his back was so painful, that he just kept asking me in kind of a weird way,” Hong remembers. “I finally picked up on it: ‘Oh, this guy is asking me for an X-ray of his back. And it's because he just wants something done.’”
People in pain may not be receptive to a conversation about wasted health care spending and medical guidelines that would let them suffer for six weeks before getting an image. Ofri often opts to discuss the potential risks of radiation exposure, which prompt patients to back off their requests for a scan. Sometimes she discusses a likely root cause — too much weight in the abdomen or poor lifting technique — and urges patients to make lifestyle changes to avoid back pain episodes in the future. She sympathizes that it isn’t really what they want to hear. “Patients just want to feel better,” Ofri says. “The situation is not very satisfying.”
Lola Butcher is a health care business and policy writer based in Missouri.