title: Co-existence of chronic fatigue syndrome with fibromyalgia syndrome in the general population. A controlled study.
abstract: OBJECTIVE
  To determine the proportion of adults with fibromyalgia syndrome (FMS) in the general population who also meet the 1988 Centre for Disease Control (CDC) criteria for chronic fatigue syndrome (CFS).
  
  
  METHODS
  Seventy-four FMS cases were compared with 32 non-FMS controls with widespread pain and 23 with localized pain, all recruited in a general population survey.
  
  
  RESULTS
  Among females, 58.0% of fibromyalgia cases met the full criteria for CFS, compared to 26.1% and 12.5% of controls with widespread and localized pain, respectively (p=0.0006). Male percentages were 80.0, 22.2, and zero, respectively (p=0.003). Compared to those with FMS alone, those meeting the case definitions for both FMS and CFS reported a worse course, worse overall health, more dissatisfaction with health, more non-CFS symptoms, and greater disease impact. The number of total symptoms and non-CFS symptoms were the best predictors of co-morbid CFS.
  
  
  CONCLUSIONS
  There is significant clinical overlap between CFS and FMS.
authors.affiliation: Department of Medicine, University of Western Ontario, London, Canada. kevin.white@lhsc.on.ca
authors.forename: K P
authors.initials: KP
authors.lastname: White
authors.forename: M
authors.initials: M
authors.lastname: Speechley
authors.forename: M
authors.initials: M
authors.lastname: Harth
authors.forename: T
authors.initials: T
authors.lastname: Ostbye
mesh_terms: D000328:Adult; D015897:Comorbidity; D015673:Fatigue Syndrome, Chronic / Q000453:epidemiology*; D005260:Female; D005356:Fibromyalgia / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D012720:Severity of Illness Index