Clinical Diagnosis of Fibromyalgia Often Disagrees With Published Criteria

By Will Boggs MD

February 22, 2019

NEW YORK (Reuters Health) - Many patients with a clinical diagnosis of fibromyalgia do not satisfy published diagnostic criteria, according to findings from rheumatology clinic attendees.

Fibromyalgia remains a controversial diagnosis, with some studies suggesting that fibromyalgia is overdiagnosed and others reporting that community physicians have limited knowledge of fibromyalgia diagnosis and criteria.

Dr. Frederick Wolfe from National Data Bank for Rheumatic Diseases and the University of Wichita School of Medicine, in Kansas, and colleagues compared expert physician diagnosis of fibromyalgia with published criteria in their study of 497 consecutive unselected rheumatology clinic attendees who completed questionnaires based on the American College of Rheumatology preliminary diagnostic criteria for fibromyalgia for clinical research.

Based on these criteria, 24.3% could be classified as having fibromyalgia. The fibromyalgia prevalence by clinician diagnosis was 20.9%, but agreement between methods was only 79.2%, with only fair agreement beyond chance agreement.

Physicians failed to identify 60 criteria-positive patients (49.6%) and incorrectly identified 43 criteria-negative patients (11.4%) as having fibromyalgia, the researchers report in Arthritis Care and Research, online February 6.

Only 58.7% of the 104 for patients clinically diagnosed with fibromyalgia actually satisfied diagnostic criteria, and 15.3% of the 393 patients not diagnosed with the condition satisfied the diagnostic criteria.

In an analysis restricted to patients with rheumatoid arthritis, systemic lupus erythematosus, or osteoarthritis, agreement ranged from poor to fair among clinicians' diagnosis and fibromyalgia criteria.

Clinicians appeared to give greater weight in making a clinical diagnosis of fibromyalgia to being a woman and to having increased symptoms and were willing to make the diagnosis despite Widespread Pain Index (WPI) and Polysymptomatic Distress (PSD) scores below the threshold for criteria diagnosis.

"It is likely that diagnosis in the community by general physicians, for whom the criteria are not as well-known, will be even more inaccurate than what we observed in this university clinic," the researchers note.

"If, as we believe, these data offer support for the observation of Walitt et al of substantial misdiagnosis in the general population, it is likely that misdiagnosis is a public health problem and one that can lead to overdiagnosis and overtreatment, as well as to inappropriate treatment of individuals not recognized to have fibromyalgia symptoms," they conclude.

Dr. Don L. Goldenberg from Oregon Health Sciences University, in Portland, and Tufts University School of Medicine, in Medford, Massachusetts, who wrote a linked editorial, told Reuters Health by email, "The diagnosis of most common conditions, like fibromyalgia, is based on subjective symptoms, which can only be ascertained from the clinical encounter."

"When a primary care physician is uncertain whether their patient is depressed, they would not apply new DSM criteria but would refer to a mental health professional to verify the diagnosis," he said. "Similarly, rheumatologists readily diagnose fibromyalgia although only recently have recognized its impact on traditional rheumatic diseases. The other piece of the diagnostic dilemma is the notion of disease versus illness, state versus trait. Once again, all common conditions, like depression, are caught in this conundrum."

Dr. Goldenberg added, "Classification criteria, such as those for fibromyalgia, may help guide a diagnosis but are primarily useful for research and epidemiological studies. As such, they should be standardized, reproducible, and easy to perform. They are designed to remove physician subjectivity whenever possible and periodic updates may accomplish these goals."

His editorial concludes, "The diagnostic gold standard for fibromyalgia will continue to be the rheumatologist's expert opinion, not classification criteria, no matter how well-refined and intentioned. This is the only way to capture the variability and severity of interrelated symptoms as they play out over time. There is no short-cut. We are the go-to experts for patients and our colleagues for the diagnosis of fibromyalgia, whether or not we readily accept that role."

Dr. Wolfe did not respond to a request for comments.


Arthritis Care Res 2019.