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Are too many patients diagnosed with fibromyalgia? The co-authors of one new study believe that close to 75% of patients who have received a clinical fibromyalgia diagnosis do not meet the 2010 Preliminary American College of Rheumatology (ACR) Criteria for Fibromyalgia.1 They say these patients are false-positive and may be taking treatments they don’t need.
The paper, “Three-Quarters of Persons in the U.S. Population Reporting a Clinical Diagnosis of Fibromyalgia Do Not Satisfy Fibromyalgia Criteria: The 2012 National Health Interview Survey,” was published in PLOS One in June 2016.2
Using information from the survey, which included data from 8,446 individuals weighted to represent 225,726,257 U.S. adults, the co-authors then developed “surrogate NHIS diagnostic criteria based on the level of polysymptomatic distress (PSD) as characterized” in the ACR criteria. The preliminary 2010 criteria are a standard for diagnosis of fibromyalgia, and the modified criteria published in 2011 are used as a mechanism for research, the paper states.
“Doctors often believe that they are able to recognize fibromyalgia without using the criteria,” says Brian Walitt, MD, MPH, one of the study’s authors. Dr. Walitt is a rheumatologist, and is a medical officer at the National Institute of Nursing Research of the National Institutes of Health in Washington, D.C. They concluded that various factors, including patient demographics, may influence whether or not someone receives a fibromyalgia diagnosis.
Patients’ Role in Diagnosis
“Some patients take an active role in the diagnostic process, recognizing their symptoms as fibromyalgia and turning to physicians to confirm their suspicions and offer a plan for treatment,” says Dr. Walitt. “Advertisements for fibromyalgia medications provide a picture of what fibromyalgia is that is not accurate. This may influence how patients describe their symptoms and how doctors made diagnostic decisions.”
Others disagree with this study’s findings. Some patients may experience varying degrees of clinical symptoms during the course of their lives and may not meet the ACR criteria at a particular point in time, particularly if treatments have worked to ease symptoms, says Daniel Clauw, MD, a rheumatologist and professor of anesthesiology, medicine, and psychiatry at the University of Michigan Division of Pain Research in Ann Arbor.
“You’d expect some discordance in prevalence, but I don’t think it’s anywhere near where the PLOS One paper says it is,” says Dr. Clauw. He believes the PSD score developed for this study is invalid. He says he believes that “they did not have the right variables in place.” He continues, “Another problem is that the symptoms of fibromyalgia occur on a continuum. Even in a study where the methodology was done well, you’d expect a certain number of people diagnosed with fibromyalgia at some point in time, if they get treatment, to have improved symptoms. It doesn’t mean that they didn’t have fibromyalgia in the past.” The fibromyalgia criteria are more applicable in research than in clinical practice, he adds.
At the University of Pittsburgh’s Center for Pain Research, Cheryl Bernstein, MD, treats fibromyalgia patients who have seen numerous physicians, including rheumatologists, for years to address pain. Most have already tried pharmacologic approaches, such as duloxetine or pregabalin, without success. Her clinic uses an interdisciplinary approach to fibromyalgia treatment, including exercise, physical or occupational therapy, cognitive-behavioral therapy, diet and medications.
“Fibromyalgia comes up frequently in my practice. By the time these patients get to me, they are severely distressed. They might have been diagnosed already, but some have gone years without a diagnosis,” says Dr. Bernstein, associate professor of anesthesiology. She confirms fibromyalgia diagnoses using a physical examination and medical history, but says she doesn’t always use the ACR criteria-based survey. Some patients have been previously diagnosed with other conditions, including depression and chronic whiplash or back pain.
“Fibromyalgia patients are very frustrated,” she says. “They think no one wants to help them, even within their own families. They may look healthy, but are in severe distress.”
Diagnostic Guideposts
Not all physicians use them, but fibromyalgia diagnosis often is made using these benchmarks from the ACR 2010 Preliminary Diagnostic Criteria, which the CDC’s website includes for “clinical diagnosis and severity classification” of patients:
- Scores on the Widespread Pain Index (WPI) >7 and a symptom severity scale (SS) >5 or WPI 3–6 and SS >9.
- Symptoms have been present at a similar level for at least three months.
- The patient does not have a disorder that would otherwise explain the pain.
Because the questionnaire variables used in the NHIS survey did not exactly match those in the criteria, Dr. Walitt says he and his fellow researchers developed surrogate diagnostic criteria and PSD scores for their study. They evaluated joints, regional pain sites and fatigue, sleep and cognitive complaints.
Of the 1.78% of individuals in the study who had reported receiving a clinical diagnosis of fibromyalgia, the researchers found that 73.5% did not meet these surrogate, NHIS fibromyalgia criteria. They further concluded that the prevalence of false-positive (F/P) fibromyalgia is 1.3%, and stated that F/P fibromyalgia is associated with mild PSD or an NHIS score of 6.2, frequent but not widespread pain, and insomnia. In addition, the F/P fibromyalgia patients in their study reported measures of work disability and medical utilization equal to those who did meet the NHIS criteria, and they determined that the most accurate demographic predictors of having F/P fibromyalgia were being female (odds ratio of 8.81), married (OR 3.27) and white (OR 1.96).
“When the first population studies of fibromyalgia came out, it was obvious that the demographics of fibromyalgia patients in the population looked very different from the fibromyalgia patients that doctors like me were seeing in rheumatology clinics and those that were participating in pharmaceutical trials of fibromyalgia medications,” says Dr. Walitt, who is also adjunct associate professor at Georgetown University. “We did this work because we wanted to have a better idea of how the fibromyalgia diagnosis is being used in the U.S., which includes understanding when it may be overused as well as when it may be underused.”
Demographic Influencers?
Such factors as obesity or smoking can worsen fibromyalgia symptoms, says Dr. Walitt, but the diagnosis “is more dependent on individual demographics than on the symptoms themselves. We suggest this is evidence that each person’s unique experience of symptoms is interpreted and affected by society and culture, which is known as social construction,” he says.
According to the study, middle-aged, Caucasian women may be overrepresented in fibromyalgia studies drawn from specialty clinics, general surveys and pharmaceutical trials, although population-based epidemiological studies show a female predominance of 2–3:1 and no important differences related to age or ethnicity.
Demographics play a role in whether or not a patient receives a fibromyalgia diagnosis, says Dr. Walitt.
“Fibromyalgia represents the presence of a particular set of symptoms of substantial severity. The NHIS data demonstrate that 75% of persons reporting a fibromyalgia diagnosis do not reach that level of symptom severity,” he says. In their study, they also found that “75% of persons with symptoms that are severe enough to meet our study’s criteria for fibromyalgia did not report a diagnosis from a health practitioner. It is likely that their symptoms are explained in other ways. This demonstrates that the medical community is not diagnosing fibromyalgia as intended by the criteria,” says Dr. Walitt.
Dr. Bernstein diagnoses fibromyalgia based on her clinical assessment and medical history. She may use the ACR modified criteria survey if a patient is skeptical of this diagnosis, and also finds the criteria helpful to quantify symptoms in some cases.
“I find it helpful for the patient, but I don’t use it for diagnosis,” says Dr. Bernstein. She does not feel that most of her fibromyalgia patients are misdiagnosed. She says most of her patients have high levels of distress and widespread pain, and have seen other physicians, including rheumatologists, perhaps for years. “We see a high level of healthcare utilization among our patients.”
Levels of distress vary widely among fibromyalgia patients, says Dr. Bernstein. She feels that her experience allows her to “come to see it quicker, and notice the variations earlier, so I am comfortable making the diagnosis.”
‘Some patients take an active role in the diagnostic process, recognizing their symptoms as fibromyalgia & turning to physicians to confirm their suspicions & offer a plan for treatment.’ —Brian Walitt, MD
According to nurse practitioner Carrie Schreibman at Oregon Health and Science University’s fibromyalgia clinic in Portland, most fibromyalgia patients referred for consultation to her clinic do meet the ACR criteria. The university uses a patient intake questionnaire developed by the hospital’s rheumatology clinic, which provides a basic assessment that is then augmented by the patient’s medical history and exam findings.
“I would say close to 100% of referred patients do have fibromyalgia,” says Ms. Schreibman. “Chronic, widespread pain is the distinguishing feature. Patients exhibit a range in overall symptom severity, but all have pain.” Many of her fibromyalgia patients have endured “intensive workups in the past with no answers and no treatment. Most patients receiving diagnosis feel validated and ready to start the treatment plan,” says Schreibman.
Whether or not a fibromyalgia patient’s widespread pain and other symptom severity reaches the criteria’s threshold at the time they present in clinic is not as important as the fact that they received this diagnosis from a medical professional at some point, says Dr. Clauw.
“Seeing this diagnosis in the patient’s medical record should prod the clinician that this is a different kind of pain that needs a different kind of treatment. It’s not pain out on the periphery. It’s not nociceptive pain. That’s the message that the criteria should be getting out there,” he says.
Fibromyalgia’s centralized “brain pain” occurs on a continuum in most patients, and may ebb and flow, says Dr. Clauw.
“It’s not phony. It’s a real medical condition. When a primary care physician recognizes it’s fibromyalgia, it helps point the patient in the right direction—and often a very different direction than they were on before they got that label,” he says. “I would not worry much about over-diagnosing fibromyalgia for now, because it is very much under-diagnosed.”
Susan Bernstein is a freelance medical journalist based in Atlanta.
References
- Wolfe F, Clauw D, Fitzcharles MA, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res. 2010 May;62(5):600–610.
- Walitt B, Katz R, Bergman M, et al. Three-quarters of persons in the U.S. population reporting a clinical diagnosis of fibromyalgia do not satisfy fibromyalgia criteria: The 2012 National Health Interview Survey. PLOS One. 9 Jun 2016;11(6):e0157235.
