Is Fibromyalgia Overdiagnosed?

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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.