Societal and individual burden of illness among fibromyalgia patients in France: Association between disease severity and OMERACT core domains

BACKGROUND Patients with fibromyalgia (FM) report widespread pain, fatigue, and other functional limitations. This study aimed to provide an assessment of the burden of illness associated with FM in France and its association with disease severity and core domains as defined by Outcome Measures in Rheumatology Clinical Trials (OMERACT) for FM. METHODS This cross-sectional, observational study recruited patients with a prior diagnosis of FM from 18 community-based physician offices in France. Patients completed questions about FM impact (Fibromyalgia-Impact Questionnaire [FIQ]), core symptoms (defined by OMERACT), health-related quality of life (EQ-5D), current overall health status (rated on a scale from 0 to 100), productivity, treatment satisfaction, and out-of-pocket expenses related to FM. Site staff recorded patients' treatment and health resource use based on medical record review. Costs were extrapolated from 4-week patient-reported data and 3-month clinical case report form data and calculated in 2008 Euros using a societal perspective. Tests of significance used the Kruskal-Wallis test or Fisher's Exact test where P < 0.05 was considered significant. RESULTS Eighty-eight patients (mean 55.2 y; female:male 74:14) were recruited. The majority of patients (84.1%) were prescribed medications for FM. Patients mainly described medications as a little/not at all effective (40.0%) or somewhat effective (52.9%). Current Overall Health rating was 52.9 (± 17.8) and FIQ total score was 54.8 (± 17.3). FIQ total score was used to define FM severity, and 17 patients scored 0- < 39 (mild FM), 33 patients 39- < 59 (moderate FM), and 38 scored 59-100 (severe FM). As FM severity level worsened, patients had poorer overall health status and perceived their prescription medications to be less effective. Average cost/FM patient was higher for severe (€10,087) vs. moderate (€6,633) or mild FM (€5,473); however, the difference was not significant. CONCLUSIONS In a sample of 88 patients with FM from France, we found that FM poses a substantial economic and human burden on patients and society. FM severity level was significantly associated with patients' health status and core symptom domains.