title: A definition-based analysis of symptoms in a large cohort of patients with chronic fatigue syndrome.
abstract: OBJECTIVE
  The Holmes and Fukuda criteria are widely used criteria all over the world, yet a specific European study regarding chronic fatigue syndrome (CFS) patient symptomatology has not been conducted so far. This study was performed to answer the need to assess the homogeneity of a large CFS population in relationship to the Fukuda or Holmes definitions and to assess the importance of a symptom severity scale.
  
  
  METHODS
  Multivariate analyses were performed to assess the symptom presentation within a fatigued population and the differences between the Fukuda and Holmes definitions compared with an excluded chronic fatigued group in a large cohort of fatigued patients.
  
  
  METHODS
  An outpatient tertiary care setting fatigue clinic in Brussels.
  
  
  METHODS
  Prevalence and severity of symptoms and signs in a CFS population and in a chronic fatigued population.
  
  
  METHODS
  A total of 2073 consecutive patients with major complaints of prolonged fatigue participated in this study. Multivariate analyses were performed to assess the symptom presentation and severity and the differences between the Fukuda and Holmes definitions.
  
  
  RESULTS
  Of the 2073 patients complaining of chronic fatigue (CF), 1578 CFS patients fulfilled the Fukuda criteria (100% of CFS group) and 951 (60.3% of the CFS group) fulfilled the Holmes criteria. Discriminant function analysis revealed that the Fukuda and Holmes definitions can be differentiated by symptom severity and prevalence. The Holmes definition was more strongly associated than the Fukuda definition with the symptoms that differentiated the CFS patients from the patients that did not comply with the CFS definitions. The inclusion of 10 additional symptoms was found to improve the sensitivity/specificity and accuracy for selection of CFS patients.
  
  
  CONCLUSIONS
  The CFS patients fulfilling the Holmes criteria have an increased symptom prevalence and severity of many symptoms. Patients fulfilling the Fukuda criteria were less severely affected patients which leads to an increase in clinical heterogeneity. Addition of certain symptoms and removal of others would strengthen the ability to select CFS patients.
authors.affiliation: VUB, Vakgroep Interne Geneeskunde, KRO gebouw niv.-1, Laarbeeklaan 101, 1090 Brussels, Belgium. pdbeck@minf.vub.ac.be
authors.forename: P
authors.initials: P
authors.lastname: De Becker
authors.forename: N
authors.initials: N
authors.lastname: McGregor
authors.forename: K
authors.initials: K
authors.lastname: De Meirleir
mesh_terms: D001530:Belgium / Q000453:epidemiology; D015331:Cohort Studies; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D015999:Multivariate Analysis; D012680:Sensitivity and Specificity