title: Reliability and validity of the delta finger-to-palm (FTP), a new measure of finger range of motion in systemic sclerosis.
abstract: OBJECTIVE
  To determine the reliability and validity of a new measure of finger motion in patients with systemic sclerosis (SSc), the 'delta finger-topalm' (delta FTP) and compare its psychometric properties to the traditional measure of finger motion, the finger-topalm (FTP).
  
  
  METHODS
  Phase 1: The reliability of the delta FTP and FTP were examined in 39 patients with SSc. Phase 2: Criterion and convergent construct validity of both measures were examined in 17 patients with SSc by comparing them to other clinical measures: Total Active Range of Motion (TAROM), Hand Mobility in Scleroderma (HAMIS), the Duruoz Hand Index (DHI), Health Assessment Questionnaire (HAQ), and modified Rodnan skin score (mRSS). Phase 3: Sensitivity to change of the delta FTP was investigated in 24 patients with early diffuse cutaneous SSc.
  
  
  RESULTS
  Both measures had excellent intra-rater and inter-rater reliability (ICC 0.92 to 0.99). Fair to strong correlations (rs=0.49-0.94) were observed between the delta FTP and TAROM, HAMIS, and DHI. Fair to moderate correlations were observed between delta FTP and HAQ components related to hand function and upper extremity mRSS. Correlations of the traditional FTP with these measures were fair to strong, but most often the delta FTP outperformed the FTP. The effect size and standardised response mean for the mean delta FTP were 0.50 and 1.10 respectively, over a 2-8 month period.
  
  
  CONCLUSIONS
  The delta FTP is a valid and reliable measure of finger motion in patients with SSc which outperforms the FTP.
authors.affiliation: Children's Hospital of Pittsburgh, Department of Pediatrics, Division of Rheumatology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Kathryn S
authors.initials: KS
authors.lastname: Torok
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Baker
authors.forename: Mary
authors.initials: M
authors.lastname: Lucas
authors.forename: Robyn T
authors.initials: RT
authors.lastname: Domsic
authors.forename: Robert
authors.initials: R
authors.lastname: Boudreau
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Medsger
mesh_terms: D005260:Female; D005384:Finger Joint / Q000503:physiopathology*; D006225:Hand / Q000503:physiopathology*; D006227:Hand Deformities, Acquired / Q000209:etiology / Q000503:physiopathology; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D045743:Scleroderma, Diffuse / Q000150:complications / Q000503:physiopathology*; D045745:Scleroderma, Limited / Q000150:complications / Q000503:physiopathology*; D012867:Skin / Q000473:pathology; D011795:Surveys and Questionnaires