[Note: At the end of the tracking period (up to 11 years), 10% of the 1,555 had significant pain improvement and 15% moderate improvement, while pain had worsened in 38.6%. Also, during the tracking period, 44% improved enough in some way at 1 or more 6-month check-up points to be diagnosis "criteria negative."]
Objective: To describe the diagnosis status and outcome of patients diagnosed with fibromyalgia (FM) by US rheumatologists.
Methods: We assessed 1,555 patients with FM with detailed outcome questionnaires during 11,006 semiannual observations for up to 11 years.
At entry, all patients satisfied American College of Rheumatology preliminary 2010 FM criteria modified for survey research.
We determined diagnosis status, rates of improvement, responder subgroups, and standardized mean differences (effect sizes) between start and study completion scores of global well-being, pain, sleep problems, and health related quality of life. (QOL)
Results: The 5-year improvement rates were: Pain 0.4 (95% CI 0.2, 0.5), Fatigue 0.4 (95% CI 0.2, 0.05), and global 0.0 (95% CI -0.1, 0.1). The standardized mean differences were patient global 0.03 (95% CI -0.02, 0.08), pain 0.22 (95% CI 0.16, 0.28), sleep problems 0.20 (95% CI 0.14, 0.25), physical component summary of the Short-form 36 (SF-36) 0.11 (95% CI -0.14, -0.07), and SF-36 mental component summary 0.03 (95% CI -0.07, 0.02).
Patients switched between criteria-positive and criteria-negative states, with 716 patients (44.0%) failing to meet criteria at least once during 4,228.5 patient-years (7,448 observations).
• About 10% of patients had substantial improvement and about 15% had moderate improvement of pain.
• Overall, FM severity worsened in 35.9% and pain in 38.6%.
Conclusion: Although we found no average clinically meaningful improvement in symptom severity overall, 25% had at least moderate improvement of pain over time.
The result that emerged from this longitudinal study was one of generally continuing high levels of self-reported symptoms and distress for most patients, but a slight trend toward improvement.
Source: Journal of Rheumatology, Jul 15, 2011;38(7). PMID: 21765102, by Walitt B, Fitzcharles MA, Hassett AL, Katz RS, Häuser W, Wolfe F. Georgetown University, Washington Hospital Center, Washington, DC; Montreal General Hospital, Division of Rheumatology, McGill University, Montreal, Quebec, Canada; Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, Michigan; Rush University Medical Center, Chicago, Illinois; Department of Psychosomatic Medicine and Psychotherapy, Technische Universität München, Munich, Germany; National Data Bank for Rheumatic Diseases and University of Kansas School of Medicine, Wichita, Kansas, USA. [Email: email@example.com]