Epidemiology

The prevalence of fibromyalgia varies greatly by population studied and surveillance method used (e.g., survey vs. clinician diagnosed, and criteria used). It is much more prevalent using surveys with standardised criteria (6.4 % vs. 1.1 %, respectively), rather than relying on physician recognition or medical record coding.[7]​ Prevalence estimates vary greatly with diagnostic criteria applied.[7][8]

Fibromyalgia is a common condition worldwide in all ethnic and socio-economic groups.[9][10][11][12][13] Studies show the prevalence in the general population to be between 0.5% and 5%.[11]

The overall prevalence of fibromyalgia in the US, using the 1990 American College of Rheumatology criteria, is around 2%.[12] The prevalence is higher in women (3.5%) than in men (0.5%), and 9 out of 10 patients with fibromyalgia are female.[12] This bias towards diagnosing almost exclusively females is related to the 1990 fibromyalgia criteria requiring a certain number of tender points (women are inherently more tender than men, so many more will meet these criteria).[8]​ When subsequent criteria (that do not rely on tender points to make the diagnosis) are applied, the female predominance is around 2:1.​[7]​​[8][14]

An increase in the prevalence of fibromyalgia to between 6% and 8% of the population has been reported.[7][14]​​[15]

Age of onset is typically between 20 and 60 years, with an average age of 35 years; prevalence increases with age.[11][12]​ Familial and genetic factors play a strong role; first-degree relatives of individuals with fibromyalgia are eight times more likely to have the condition.[16]

Fibromyalgia can also present in childhood, but this patient group is not addressed specifically in this topic.

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