title: Using Optimal Test Assembly Methods for Shortening Patient-Reported Outcome Measures: Development and Validation of the Cochin Hand Function Scale-6: A Scleroderma Patient-Centered Intervention Network Cohort Study.
abstract: To develop and validate a short form of the Cochin Hand Function Scale (CHFS), which measures hand disability, for use in systemic sclerosis, using objective criteria and reproducible techniques.
  
  
  
  Responses on the 18-item CHFS were obtained from English-speaking patients enrolled in the Scleroderma Patient-Centered Intervention Network Cohort. CHFS unidimensionality was verified using confirmatory factor analysis, and an item response theory model was fit to CHFS items. Optimal test assembly (OTA) methods identified a maximally precise short form for each possible form length between 1 and 17 items. The final short form selected was the form with the least number of items that maintained statistically equivalent convergent validity, compared to the full-length CHFS, with the Health Assessment Questionnaire (HAQ) disability index (DI) and the physical function domain of the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29).
  
  
  
  There were 601 patients included. A 6-item short form of the CHFS (CHFS-6) was selected. The CHFS-6 had a Cronbach's alpha of 0.93. Correlations of the CHFS-6 summed score with HAQ DI (r = 0.79) and PROMIS-29 physical function (r = -0.54) were statistically equivalent to the CHFS (r = 0.81 and r = -0.56). The correlation with the full CHFS was high (r = 0.98).
  
  
  
  The OTA procedure generated a valid short form of the CHFS with minimal loss of information compared to the full-length form. The OTA method used was based on objective, prespecified criteria, but should be further studied for viability as a general procedure for shortening patient-reported outcome measures in health research.
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, and McGill University, Montreal, Quebec, Canada.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Levis
authors.affiliation: New York University, New York. daphna.harel@nyu.edu.
authors.forename: Daphna
authors.initials: D
authors.lastname: Harel
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, and McGill University, Montreal, Quebec, Canada, and Radboud University, Nijmegen, The Netherlands.
authors.forename: Linda
authors.initials: L
authors.lastname: Kwakkenbos
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital.
authors.forename: Marie-Eve
authors.initials: ME
authors.lastname: Carrier
authors.affiliation: Université Paris Descartes, Assistance Publique-Hôpitaux de Paris, and Hôpital Cochin, Paris, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Mouthon
authors.affiliation: Université Paris Descartes, Assistance Publique-Hôpitaux de Paris, Hôpital Cochin, and IFR Handicap INSERM, Paris, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Poiraudeau
authors.affiliation: McGill University, Montreal, Quebec, Canada.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Bartlett
authors.affiliation: University of Michigan Scleroderma Program, Ann Arbor.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Khanna
authors.affiliation: San Diego State University/University of California, San Diego Joint Doctoral Program in Clinical Psychology, San Diego, California.
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: Malcarne
authors.affiliation: Scleroderma Society of Ontario, Hamilton, and Scleroderma Society of Canada, Ottawa, Ontario, Canada.
authors.forename: Maureen
authors.initials: M
authors.lastname: Sauve
authors.affiliation: Sint Maartenskliniek, Nijmegen, The Netherlands.
authors.forename: Cornelia H M
authors.initials: CH
authors.lastname: van den Ende
authors.affiliation: University of New Mexico, Albuquerque.
authors.forename: Janet L
authors.initials: JL
authors.lastname: Poole
authors.affiliation: Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Anne A
authors.initials: AA
authors.lastname: Schouffoer
authors.affiliation: NVLE Dutch patient organization for systemic autoimmune diseases, Utrecht, The Netherlands.
authors.forename: Joep
authors.initials: J
authors.lastname: Welling
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, and McGill University, Montreal, Quebec, Canada.
authors.forename: Brett D
authors.initials: BD
authors.lastname: Thombs
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004185:Disability Evaluation; D005163:Factor Analysis, Statistical; D005260:Female; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D000071066:Patient Reported Outcome Measures; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000503:physiopathology*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult