[The prevalence of fibromyalgia and chronic widespread musculoskeletal pain in Iceland.].

Objective: To determine the prevalence of fibromyalgia and chronic widespread musculoskeletal pain (CWP) in Iceland in two demographic different areas.
Material and Methods: Population based prevalence study on 1200 females and 1200 males 18-79 years old in South-West- and South-Iceland. Established musculoskeletal pain questionnaire and telephone screening of nonresponders was used. Tender point examination was done on the subjects with CWP and the diagnosis of fibromyalgia was made in accordance with the American College of Rheumatology (ACR) 1990 criteria.
Results: The prevalence of fibromyalgia in females based on 60.4% of the sample is 9.8%. The comparable prevalence in males based on 46.4% of the sample is 1.3%. The prevalence of CWP is 26.9% in females and 12.9% in males. A sharp increase in the prevalence of fibromyalgia and CWP in females is seen in the age group 31-40 compared with the age group 18-30. For female responders a statistical higher prevalence of CWP but not fibromyalgia is seen in South-West-Iceland, compared with South-Iceland. No regional differences were seen for males.
Conclusion: The prevalence of fibromyalgia and CWP is very high in Iceland. A matter of special concern is the high prevalence in young females. Possible causes are long working hours and stressful living conditions.