Results

A total of 2,529 FM patients with 79,570 observations or clinical visits were evaluated. Four main classes of FM patients were identified: Class 1) regional FM with classic symptoms; Class 2) generalized FM with increasing widespread pain and some additional symptoms; Class 3) FM with advanced and associated conditions, increasing widespread pain, increased sleep disturbance, and chemical sensitivity; and Class 4) FM secondary to other conditions.

Conclusion

FM may be represented as a disease continuum, with identifiable classes and subclasses based on pain and symptom severity, specific comorbidities, and use of clinical procedures. Patients demonstrated increases in symptom severity and region of pain by class, suggesting that the FM continuum tracks with disease progression over time. Additional studies are warranted to evaluate and better define the classes by severity with the goal of informing potential approaches to patient evaluation and management. Such an understanding and characterization of how FM patients progress through their disease may enhance diagnosis and help optimize treatment, potentially leading to improved patient outcomes and reductions in the health care system burden.