Study Finds Discrepancy Between Clinician Diagnosis of Fibromyalgia and Disease Criteria

A recent article published in Arthritis Care & Research found a significant difference between the disease criteria for fibromyalgia and how rheumatologists diagnose it.

“Recent studies have suggested that fibromyalgia is inaccurately diagnosed in the community, and that ~75% of persons reporting a physician diagnosis of fibromyalgia would not satisfy published criteria,” the researchers observed.

The study took place in a university rheumatology clinic and included nearly 500 patients who all completed the Multidimensional Health Assessment Questionnaire (MD‐HAQ) and the 2010 American College of Rheumatology preliminary diagnostic criteria modified for self‐administration.

Among the 497 patients, about a quarter (n = 121, 24.3%) met the criteria for fibromyalgia, and 104 (20.9%) received a clinician International Classification of Diseases (ICD) fibromyalgia diagnosis. Clinician-criteria agreement was 79.2%, but agreement beyond chance based on a kappa score was only fair (κ = 0.41). Among criteria-positive patients, clinicians did not diagnose half (n = 60, 49.6%), and 43 patients without criteria (11.4%) received an incorrect diagnosis. A separate analysis of rheumatoid arthritis patients (n = 88) yielded a 0.32 kappa value, which the study authors identified as slight to fair clinician-criteria agreement. Higher polysymptomatic distress scores and criteria-based diagnosis were strongly correlated with more abnormal MD-HAQ clinical scores. Patients more likely to receive a clinician’s diagnosis than to meet fibromyalgia criteria were female patients and those with more symptoms but fewer pain areas.

“Fibromyalgia criteria were easy to use, but problems regarding clinician bias, meaning of a fibromyalgia diagnosis, and the validity of physician diagnosis were substantial,” the study authors wrote.

Prevalence and Diagnosis of Fibromyalgia

According to the American College of Rheumatology (ACR), about 2% to 4% of the population has fibromyalgia, and women are at higher risk. Fibromyalgia often starts in middle age, and those with a prior rheumatic condition—such as osteoarthritis, lupus, rheumatoid arthritis, or ankylosing spondylitis—are more likely to develop the disease. The disease does not have one specific cause, and it is not from an autoimmune, inflammation, joint, or muscle disorder. Experts believe the central nervous system may play a role.

Per the ACR, criteria needed to make a fibromyalgia diagnosis include:

1. Week-long pain and symptoms, based on the total of number of painful areas out of 19 parts of the body plus severity level of fatigue, waking unrefreshed, and cognitive problems
2. At least three months of symptoms at a similar level
3. No evidence that another condition is causing the pain and symptoms

There is no specific test used to diagnose fibromyalgia, and patients experience symptoms differently. X-rays and lab tests may be used to rule out another disease. The most common symptom of fibromyalgia is chronic widespread pain.

Source: Arthritis Care & Research