title: Responsiveness and minimally important differences for selected Persian-version of outcome measures used in patients with patellofemoral pain syndrome.
abstract: OBJECTIVE
  To investigate the responsiveness and determine the minimally important differences (MID) of Persian versions of the Kujala patellofemoral scale (KPS), lower extremity functional scale (LEFS), and functional index questionnaire (FIQ) in patients with patellofemoral pain syndrome (PFPS).
  
  
  METHODS
  Outcome measures including the Persian KPS, LEFS, and FIQ were administered to 233 patients at baseline and then again 4 weeks after physiotherapy. Moreover, the 7-point global rating scale was completed by the patients at 4 weeks. Responsiveness was evaluated using the correlation analysis and the receiver operating characteristics (ROC) method.
  
  
  RESULTS
  Correlation analysis showed that the relationship of all outcome measures with the global rating scale falls within the fair range of relationship (Gamma = 0.26-0.40). Moreover, the results of ROC analysis showed that the all outcome measures have acceptable high responsiveness index. Furthermore, the MIDs of 9.5, 4.5, and 1.5 points were obtained for the Persian KPS, LEFS, and FIQ, respectively.
  
  
  CONCLUSIONS
  The Persian-versions of all outcome measures are responsive for evaluating change following physiotherapy intervention. The MID values obtained in this study will help the clinicians and researchers to determine if a patient with PFPS has experienced a true change following a physiotherapy intervention. Implications for Rehabilitation Persian-versions of the KPS, LEFS, and FIQ can be used as three "responsive" outcome measures in clinical studies of patients with patellofemoral pain syndrome (PFPS). These assessment tools have clinical relevance for rehabilitation specialists working on patients with PFPS. The minimally important differences provide valuable information for the clinicians and researchers to make decision about the identification of a clinical change in health status of patients with PFPS.
authors.affiliation: Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences , Ahvaz , Iran .
authors.forename: Hossein
authors.initials: H
authors.lastname: Negahban
authors.forename: Neda
authors.initials: N
authors.lastname: Mostafaee
authors.forename: Soheil Mansour
authors.initials: SM
authors.lastname: Sohani
authors.forename: Masumeh
authors.initials: M
authors.lastname: Hessam
authors.forename: Hamed
authors.initials: H
authors.lastname: Tabesh
authors.forename: Ali
authors.initials: A
authors.lastname: Montazeri
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007492:Iran; D007802:Language; D008137:Longitudinal Studies; D008297:Male; D010147:Pain Measurement / Q000379:methods*; D046788:Patellofemoral Pain Syndrome / Q000534:rehabilitation*; D026741:Physical Therapy Modalities / Q000592:standards*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D016896:Treatment Outcome; D055815:Young Adult
keywords: Function; Kujala Patellofemoral Scale; minimally important differences; pain; responsiveness