In 2016, a revised version of the 2010 American College of Rheumatology fibromyalgia (FM) criteria and the 2011 self-report (survey) FM criteria were published. The 2016 criteria preserved the distinction between physician and patient criteria, but made the individual criteria items identical, added a "generalized pain" criterion, and changed ascertainment and scoring methods, among other changes. In this study, we evaluated diagnostic differences relating to 2016 changes.
We used the National Data Bank for Rheumatic Diseases and evaluated 16,987 participants with painful rheumatic disorders using the 2011 and 2016 methodologies.
There were 4731 patients (27.9%) who satisfied the 2011 criteria and 4077 (24.0%) the 2016 revision. This resulted in agreement in 96.2% of cases and disagreement in 3.9%. All disagreements occurred in the 4731 2011-positive cases who failed to meet the 2016 criteria. This result came about because 654 (13.8%) of the 2011-positive cases failed to meet the new generalized pain requirement. When using the approximate polysymptomatic distress diagnostic method, diagnostic misclassification ranged between 7% and 13%.
The 2016 FM criteria further refined and increased the usefulness of symptom-based diagnosis of FM by excluding patients with regional pain syndromes. However, these changes, useful as they are, underscore the social construction of symptom-based diagnosis and the inherent limitations in reliability and validity associated with FM criteria.