To estimate the prevalence of fibromyalgia (FM) syndrome in the French general population.
A validated French version of the London Fibromyalgia Epidemiology Study Screening Questionnaire (LFESSQ) was administered via telephone to a representative community sample of 1014 subjects aged over 15 years, selected by the quota method. A positive screen was defined as: (1) meeting the 4-pain criteria alone (LFESSQ-4), or (2) meeting both the 4-pain and 2-fatigue criteria (LFESSQ-6). To estimate the positive predictive value of LFESSQ-4 and LFESSQ-6, this questionnaire was submitted to a sample of rheumatology outpatients (n=178), who were then examined by a trained rheumatologist to confirm or exclude the diagnosis of FM according to the 1990 American College of Rheumatology criteria. The prevalence of FM in the general population was estimated by applying the predictive positive value to eligible community subjects (i.e., positive screens).
In the community sample, 9.8% and 5.0% screened positive for LFESSQ-4 and LFESSQ-6, respectively. Among rheumatology outpatients, 47.1% screened positive for LFESSQ-4 and 34.8% for LFESSQ-6 whereas 10.6% were confirmed FM cases. Based on positive screens for LFESSQ-4, the prevalence of FM was estimated at 2.2% (95% CI 1.3-3.1) in the French general population. The corresponding figure was 1.4 % (95% CI 0.7-2.1) if positive screens for LFESSQ-6 were considered.
Our findings suggest that FM is also a major cause of widespread pain in France since a point prevalence of 1.4% would translate in approximately 680,000 patients.