A POPULATION STUDY OF THE INCIDENCE OF FIBROMYALGIA AMONG WOMEN AGED 26-55 YR

In a population survey, we assessed the incidence of fibromyalgia (FM) among females. A screening questionnaire about pain was distributed t wice (in 1990 and 1995) to 2498 females aged 20-49 yr, living in South Norway. A positive answer classified the responder as positive, merel y negative answers as negative. One hundred females converting from ne gative to positive responders and 100 females remaining negative respo nders (controls) underwent a structural interview and examination for tender points (TP). Of the 870 negative responders in 1990, 717 answer ed the questionnaire in 1995. Of these, 523 were still negative respon ders, while 194 were positive converters. Twelve of the converters dev eloped FM and none of the controls. The calculated annual incidence of FM in females was 583/100 000. This rather high incidence is most lik ely explained by the design of the study, also detecting cases usually not seen in hospital settings.