Using Revised 2016 Criteria to Diagnose Fibromyalgia is Reliable and Valid, Study Says

Using Revised 2016 Criteria to Diagnose Fibromyalgia is Reliable and Valid, Study Says

The revised 2016 clinical criteria to diagnose fibromyalgia are reliable and valid, and improve on the previous version, a new study shows.

The study, titled “Performance of the revised 2016 fibromyalgia diagnostic criteria in Korean patients with fibromyalgia,” was published in the International Journal of Rheumatic Diseases.

The first criteria were developed in 1990 by the American College of Rheumatology (ACR) to help physicians differentiate fibromyalgia (FM) from other chronic, widespread pain syndromes and make accurate diagnoses.

Since then, ACR continues to update the guidelines for FM diagnosis at yearly intervals as new research emerges.

The most recent update was released in 2016 with new criteria to minimize misdiagnosis of regional pain disorders and remove the previously confusing recommendations on diagnostic exclusions.

To date, no study has assessed whether the 2016 criteria are better than the previous criteria (2010/2011).

Therefore, using a Korean version of the 2016 revised criteria, a group of researchers explored whether these new guidelines were superior to the original in making accurate diagnoses of FM.

The study enrolled 86 FM patients and 89 patients with various rheumatological disorders that were similar and could potentially be confused for each other, including rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, and myofascial pain syndrome.

All patients were asked to complete a questionnaire that included the revised Fibromyalgia Impact Questionnaire (FIQ), the EuroQol five‐dimensional questionnaire (EQ‐5D), and the Multidimensional Health Assessment Questionnaire (MD‐HAQ).

The FIQ helps measure the functional status of FM patients, the EQ-5D helps measure health-related quality of life, and MD-HQ helps assess advanced activities of daily living and psychological status.

The test‐retest reliability of the revised criteria was assessed in 30 patients after two weeks using two variables — Spearman coefficient and Cronbach’s alpha. A score of zero indicates no reliability, and a score of 1 indicates perfect reliability.

Test-retest reliability measures consistency of a test. If the same test was given twice to the same people at different times, test-retest reliability indicates the likelihood that the scores would be the same.

The Spearman coefficient ranged from 0.616 to 0.910 and the Cronbach’s alpha was 0.942 for the revised criteria, indicating that it had excellent reliability.

Additionally, the revised criteria correlated significantly with the revised FIQ, the EQ‐5D, and the MD‐HAQ scores.

Using this criteria, researchers were able to diagnose FM in 94.2% of patients with a prior diagnosis of FM, and in 10.1% of those with other rheumatological disorders.

The criteria’s sensitivity was 93.1% and the specificity was 90.7%. Test sensitivity indicates the ability to correctly identify those with the disease, while specificity is its ability to correctly identify those without the disease.

“The revised criteria are reliable and valid when used to diagnose patients with FM, and are better than the previous criteria,” the authors concluded.

“Thus, we believe that the 2016 criteria can be used to diagnose FM in individuals with chronic pain encountered in clinical practice,” they said.