title: Minimal (clinically) important differences for the Fatigue Assessment Scale in sarcoidosis.
abstract: OBJECTIVE
  The usefulness of any questionnaire in clinical management and research trials depends on its ability to indicate a likelihood of treatment success during follow-up. The Minimal Clinically Important Difference (MCID) reflects a clinically relevant change score. The aim of this study was to estimate the MCID for the Fatigue Assessment Scale (FAS) in patients with sarcoidosis.
  
  
  METHODS
  Outpatients (n = 321) of the ild care team of the Department of Respiratory Medicine of the Maastricht University Medical Centre, The Netherlands, participated in this prospective follow-up study. Anchor-based and distribution-based methods were used to estimate the MCID. Based on the anchor Physical Quality of Life, a Receiver Operating Characteristic (ROC) was obtained. The distribution-based methods consisted of the Effect Size and Standard Error Measurement (SEM).
  
  
  RESULTS
  The anchor-based MCID found with ROC was 3.5. The distribution-based methods showed that the corresponding change scores in the FAS for a small effect was 4.2. The SEM criterion was 3.6 points change in the FAS.
  
  
  CONCLUSIONS
  Based on the anchor-based and distribution-based methods, the MCID is a 4-point difference on the FAS. This MCID can be used in the follow-up of fatigue (FAS) in clinical trials and in the management of individual sarcoidosis cases.
authors.affiliation: Center of Research on Psychology in Somatic Diseases (CoRPS), Department of Medical Psychology, Tilburg University, Tilburg, The Netherlands.
authors.forename: Willemien P E
authors.initials: WP
authors.lastname: de Kleijn
authors.forename: Jolanda
authors.initials: J
authors.lastname: De Vries
authors.forename: Petal A H M
authors.initials: PA
authors.lastname: Wijnen
authors.forename: Marjolein
authors.initials: M
authors.lastname: Drent
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005221:Fatigue / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009426:Netherlands; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology*; D017565:Sarcoidosis, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards*; D016896:Treatment Outcome