Fibromyalgia is a chronic condition that affects millions of people in the US. However, the authors of a new study now warn that a significant number of people who have received a diagnosis may not, in reality, have this condition.

People with fibromyalgia experience pain all over the body, as well as fatigue, headaches, and increased sensitivity to painful stimuli.

Other symptoms may include depression and anxiety, poor sleep, and problems with memory or thinking.

According to the Centers for Disease Control and Prevention (CDC), fibromyalgia affects approximately 4 million adults in the US, which equates to about 2% of the adult population.

To diagnose this condition, a physician is likely to ask about a person's medical history. They may also perform a physical exam and request X-rays and blood tests.

Although fibromyalgia is prevalent, new research has found that doctors have misdiagnosed many people as having this condition. Dr. Frederick Wolfe from the National Data Bank for Rheumatic Diseases in Wichita, KS led the study.

The findings, which appeared today in the journal Arthritis Care & Research, indicate that using textbook criteria to diagnose someone can lead to a different prognosis than using a clinician's in-person assessment.

Many incorrect or missed diagnoses

In this study, the researchers worked with 497 people attending a rheumatology clinic. All of these individuals filled in both a health assessment questionnaire and a questionnaire that the American College of Rheumatology use to assess a person for fibromyalgia symptoms.

The participants also received consultations and diagnoses from rheumatology clinicians.

On assessing the results of these evaluations, the researchers found that only 121 (or 24.3%) of the initial 497 participants received a fibromyalgia diagnosis from a rheumatology clinician.

When they came to compare the clinicians' evaluations with the questionnaire-based evaluation results, the researchers found that they coincided in 79.2% of cases.

However, the researchers note that agreement beyond chance between these two types of assessment was only fair, with doctors missing 60 (or 49.6%) of the fibromyalgia cases according to criteria and misdiagnosing 43 (or 11.4%) of the individuals who did not match the criteria for this condition.

"We have recently studied the same issue in 3,000 primary care patients and found about the same results," notes Dr. Wolfe. "Therefore," he adds, "our conclusions are secure."

Physician's diagnosis still 'gold standard'

In the editorial that featured alongside the study paper, Dr. Don Goldenberg from Oregon Health & Science University in Portland, OR, writes that the current study's findings suggest that published criteria are more accurate when it comes to diagnosing fibromyalgia.

However, he emphasizes that published criteria, no matter how well-developed, cannot replace the opinion of a physician who is evaluating an individual in person and assessing numerous health variables.

"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."

—Dr. Don Goldenberg

"This is the only way to capture the variability and severity of interrelated symptoms as they play out over time," Dr. Goldenberg writes.