A two-year study of fibromyalgia and chronic pain by an international team of investigators concluded that fibromyalgia patients experience symptom ebbs and flows that affect diagnosis and treatment.
The study, “Progression of fibromyalgia: results from a 2-year observational fibromyalgia and chronic pain study in the US,“ published online by the Journal of Pain Research, aimed to better understand fibromyalgia’s progression, based on findings from a previous study that indicated 20 percent to 47 percent of fibromyalgia (FM) patients no longer meet the disease’s standard definition two years after diagnosis.
Researchers followed 226 patients who met the criteria for participation. They had completed online the London Fibromyalgia Epidemiology Study Screening Questionnaire, used to check for CWP (bilateral pain above/below the waist, experienced in the preceding three months and lasting for at least one week), visited a physician and were either found or not found to have FM, and completed a patient-reported outcomes questionnaire.
Subjects were then categorized into three groups: those who screened positive for CWP and received a diagnosis of FM (FM+CWP+), those who screened positive for CWP but were not diagnosed with FM (FM-CWP+), and those with FM who screened negative for CWP (FM-CWP-).
About two years later, subjects were reassessed at the same study site and answered the same questionnaires.
Of the 76 FM+CWP+ subjects, 56 (73.7 percent) still met the FM study diagnostic definition at follow-up. The remaining 20 no longer did (of which 11 became FM-CWP-, and nine became FM-CWP+).
Ten people (two from FM-CWP- and eight from FM-CWP+) transitioned into the FM+CWP+ group at follow-up, reporting more tender points and pain interference with sleep, and generally worse physical function compared with subjects who did not transition to FM+CWP+.
Most (76.7 percent) of the people who transitioned into, or out of, FM+CWP+ experienced changes in CWP, the number of positive tender points.
Based on the findings, the investigators suggest that some FM+CWP+ patients experience fluctuations in symptom intensity and severity over time, likely reflecting the “waxing and waning nature” of FM that affects both the disease’s diagnosis and its treatment.
The authors observed that their results support previous research suggesting that while FM is a chronic illness, it is marked by periods of improvement following treatment and diagnosis. They also emphasized that the majority of FM+CWP+ patients at baseline were also CWP+ and rediagnosed at follow-up. However, facts pointed toward the consensus that FM patients in the study were generally stable over the two-year study period.
Also at the follow-up assessment, 10 people who had not met diagnostic criteria for FM at baseline now did. Data from these 10 suggested that a high number of FM tender points, modified ACR 2010 criteria scores (a measure of symptom severity), suboptimal physical function, and poor sleep due to pain may be present in patients who develop FM.
Results also concurred with previous research finding that the number of painful regions in individuals presenting with no chronic pain and chronic regional pain at baseline was the strongest predictor of CWP development at a follow-up of three years.
The researchers noted that results of both current and previously published studies suggest that some FM patients may experience short- or long-term remission of FM symptoms, and that the concept of FM being part of a larger continuum of central pain disorders, identified as central sensitivity syndromes, may play a role in symptom variation.
Among patients who no longer met the FM definition at follow-up, only one had stopped taking a medication class. Most changes in medication use between baseline and follow-up in these patients involved the initiation of new medication classes, suggesting these new treatments contributed to symptom relief and a person’s change in FM status.
Accordingly, proactive management (both pharmacologic and nonpharmacologic) in the initial years following FM diagnosis could influence long-term outcomes in some patients, although the researchers caution that the findings are preliminary and additional research on predictors of CWP, and FM in general, is needed.