title: Determining the Minimal Clinically Important Difference for 6-Minute Walk Distance in Fibromyalgia.
abstract: The aim of this study was to estimate the minimal clinically important difference (MCID) for 6-min walk distance (6MWD) in patients with fibromyalgia.
  
  
  
  Data from a recently completed trial that included 187 patients who completed the 6-min walk test, Fibromyalgia Impact Questionnaire (FIQ), and Short-Form 36 (SF36) at 12 and 36 wks were used to examine longitudinal changes in 6MWD. An anchor-based approach that used linear regression analyses was used to determine the MCID for 6MWD, using the total FIQ score (FIQ-Total) and SF36-physical function domain as clinical anchors.
  
  
  
  The mean (SD) change in 6MWD from baseline to week 36 was 34.4 (65.2) m (P < 0.001). The anchor-based MCIDs for the 6MWD were 156 and 167 m for the FIQ and SF36-physical function domain, respectively. These MCIDs correspond with clinically meaningful improvements in FIQ (14% reduction) and SF36-physical function domain (10-point increase).
  
  
  
  The MCID for 6MWD in patients with fibromyalgia was 156 to 167 m. These findings provide the first evidence of the change in 6MWD that is perceived by patients to be clinically meaningful. Further research using other MCID calculation methods is needed to refine estimates of the MCID for 6MWD in patients with fibromyalgia.
authors.affiliation: From the Department of Kinesiology, Indiana University-Purdue University, Indianapolis (ASK); Department of Biostatistics, Indiana University, Indianapolis (JES); and Division of Rheumatology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina (DCA).
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Kaleth
authors.forename: James E
authors.initials: JE
authors.lastname: Slaven
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Ang
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D000071081:Minimal Clinically Important Difference; D011795:Surveys and Questionnaires; D016138:Walking