title: Symptoms of autonomic dysfunction in chronic fatigue syndrome.
abstract: BACKGROUND
  Chronic fatigue syndrome (CFS) is common and its cause is unknown.
  
  
  OBJECTIVE
  To study the prevalence of autonomic dysfunction in CFS, and to develop diagnostic criteria.
  
  
  METHODS
  Cross-sectional study with independent derivation and validation phases.
  
  
  METHODS
  Symptoms of autonomic dysfunction were assessed using the Composite Autonomic Symptom Scale (COMPASS). Fatigue was assessed using the Fatigue Impact Scale (FIS). Subjects were studied in two groups: phase 1 (derivation phase), 40 CFS patients and 40 age- and sex-matched controls; phase 2 (validation phase), 30 CFS patients, 37 normal controls and 60 patients with primary biliary cirrhosis.
  
  
  RESULTS
  Symptoms of autonomic dysfunction were strongly and reproducibly associated with the presence of CFS or primary biliary cirrhosis (PBC), and correlated with severity of fatigue. Total COMPASS score >32.5 was identified in phase 1 as a diagnostic criterion for autonomic dysfunction in CFS patients, and was shown in phase 2 to have a positive predictive value of 0.96 (95%CI 0.86-0.99) and a negative predictive value of 0.84 (0.70-0.93) for the diagnosis of CFS.
  
  
  CONCLUSIONS
  Autonomic dysfunction is strongly associated with fatigue in some, but not all, CFS and PBC patients. We postulate the existence of a 'cross-cutting' aetiological process of dysautonomia-associated fatigue (DAF). COMPASS >32.5 is a valid diagnostic criterion for autonomic dysfunction in CFS and PBC, and can be used to identify patients for targeted intervention studies.
authors.affiliation: Fatigue Interest group and Liver Research Group, Institute for Cellular Medicine, University of Newcastle, Newcastle, UK. julia.newton@nuth.nhs.uk
authors.forename: J L
authors.initials: JL
authors.lastname: Newton
authors.forename: O
authors.initials: O
authors.lastname: Okonkwo
authors.forename: K
authors.initials: K
authors.lastname: Sutcliffe
authors.forename: A
authors.initials: A
authors.lastname: Seth
authors.forename: J
authors.initials: J
authors.lastname: Shin
authors.forename: D E J
authors.initials: DE
authors.lastname: Jones
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D015673:Fatigue Syndrome, Chronic / Q000150:complications*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012720:Severity of Illness Index