Fibromyalgia Outcomes Over Time: Results from a Prospective Observational Study in the United States

Abstract

Background: Longitudinal research on outcomes of patients with fibromyalgia is limited.

Objective: To assess clinician and patient-reported outcomes over time among fibromyalgia patients.

Methods: At enrollment (Baseline) and follow-up (approximately 2 years later), consented patients were screened for chronic widespread pain (CWP), attended a physician site visit to determine fibromyalgia status, and completed an online questionnaire assessing pain, sleep, function, health status, productivity, medications, and healthcare resource use.

Results: Seventy-six fibromyalgia patients participated at both time points (at Baseline: 86.8% white, 89.5% female, mean age 50.9 years, and mean duration of fibromyalgia 4.1 years). Mean number of tender points at each physician visit was 14.1 and 13.5, respectively; 11 patients no longer screened positive for CWP at follow-up. A majority reported medication use for pain (59.2% at Baseline, 62.0% at Follow-up). The most common medication classes were opioids (32.4%), SSRIs (16.9%), and tramadol (14.1%) at Follow-up. Significant mean changes over time were observed for fibromyalgia symptoms (modified American College of Rheumatology 2010 criteria: 18.4 to 16.9; P=0.004), pain interference with function (Brief Pain Inventory-Short Form: 5.9 to 5.3; P=0.013), and sleep (Medical Outcomes Study-Sleep Scale: 58.3 to 52.7; P=0.004). Patients achieving ≥2 point improvement in pain (14.5%) experienced greater changes in pain interference with function (6.8 to 3.4; P=0.001) and sleep (62.4 to 51.0; P=0.061).

Conclusion: Fibromyalgia patients reported high levels of burden at both time points, with few significant changes observed over time. Outcomes were variable among patients over time and were better among those with greater pain improvement.

Keywords: Burden of illness; Chronic widespread pain; Clinician-reported outcomes; Fibromyalgia; Health resource use; Outcome assessment; Patient-reported outcomes; Quality of life; Treatment patterns.

Fig. (1)

Study flow diagram. ^* Due to lack of valid e-mail address or Baseline site closure, 2 patients were not eligible to participate in Follow-up. ^† Patients who were unable to attend the site visit at Follow-up were invited to complete the online questionnaire only; however, given the patients’ fibromyalgia status/diagnosis was unknown at Follow-up, these patients were excluded from this analysis.

Fig. (2)

Medication Use for Pain Over the Past 3 Months by Class at Baseline and Follow-up. Abbreviations: misc., miscellaneous; NSAID, nonsteroidal anti-inflammatory drug; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor. ^*No statistically significant differences over time were observed. ^†“Opioids” class includes weak short-acting, strong short-acting, and long-acting and extended-release opioids.