title: The efficacy of guided self-instruction for patients with idiopathic chronic fatigue: A randomized controlled trial.
abstract: OBJECTIVE
  To determine the efficacy of a cognitive-behavioral intervention for patients meeting U.S. Centers for Disease Control and Prevention (CDC) criteria for idiopathic chronic fatigue (ICF). ICF is thought to be a less severe disorder than chronic fatigue syndrome (CFS). The intervention consisted of a booklet with self-instructions combined with e-mail contact with a therapist.
  
  
  METHODS
  Randomized controlled trial conducted at an outpatient facility. All patients suffered from severe and persistent fatigue with moderate impairment levels or fewer than 4 additional symptoms. Patients were randomly allocated to either guided self-instruction or a wait-list control group. Primary outcome measures were fatigue severity assessed with the Checklist Individual Strength and level of overall impairment assessed with the Sickness Impact Profile. Outcome measures were assessed prior to randomization and following treatment or wait-list control group.
  
  
  RESULTS
  One hundred patients were randomly allocated to the intervention or a wait-list control group and 95 completed second assessment. An intention-to-treat analysis showed significant treatment effects for fatigue severity (-8.98, 95% confidence interval [CI] [-13.99, -3.97], Cohen's d = 0.68, p < .001) and for overall impairment (-317.19, 95% CI [-481.70, -152.68], Cohen's d = 0.53, p < .01) in favor of the intervention. The number of additional symptoms and overall impairment at baseline did not moderate posttreatment fatigue severity. Baseline overall impairment moderated posttreatment impairment.
  
  
  CONCLUSIONS
  Patients with ICF can be treated effectively with a minimal intervention. This is relevant as ICF is more prevalent than CFS and treatment capacity is limited.
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center.
authors.forename: A
authors.initials: A
authors.lastname: Janse
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center.
authors.forename: J F
authors.initials: JF
authors.lastname: Wiborg
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center.
authors.forename: G
authors.initials: G
authors.lastname: Bleijenberg
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center.
authors.forename: M
authors.initials: M
authors.lastname: Tummers
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center.
authors.forename: H
authors.initials: H
authors.lastname: Knoop
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D057189:Checklist; D015928:Cognitive Behavioral Therapy; D005221:Fatigue / Q000517:prevention & control*; D015673:Fatigue Syndrome, Chronic / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014850:Waiting Lists