title: Interrater reliability of the Wolf Motor Function Test-Functional Ability Scale: why it matters.
abstract: BACKGROUND
  One important objective for clinical trialists in rehabilitation is determining efficacy of interventions to enhance motor behavior. In part, limitation in the precision of measurement presents a challenge. The few valid, low-cost observational tools available to assess motor behavior cannot escape the variability inherent in test administration and scoring. This is especially true when there are multiple evaluators and raters, as in the case of multisite randomized controlled trials (RCTs). One way to enhance reliability and reduce variability is to implement rigorous quality control (QC) procedures.
  
  
  OBJECTIVE
  This article describes a systematic QC process used to refine the administration and scoring procedures for the Wolf Motor Function Test (WMFT)-Functional Ability Scale (FAS).
  
  
  METHODS
  The QC process, a systematic focus-group collaboration, was developed and used for a phase III RCT, which enlisted multiple evaluators and an experienced WMFT-FAS rater panel.
  
  
  RESULTS
  After 3 staged refinements to the administration and scoring instructions, we achieved a sufficiently high interrater reliability (weighted κ = 0.8).
  
  
  CONCLUSIONS
  A systematic focus-group process was shown to be an effective method to improve reliability of observational assessment tools for motor behavior in neurorehabilitation. A reduction in noise-related variability in performance assessments will increase power and potentially lower the number needed to treat. Improved precision of measurement can lead to more cost-effective and efficient clinical trials. Finally, we suggest that improved precision in measures of motor behavior may provide more insight into recovery mechanisms than a single measure of movement time alone.
authors.affiliation: Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Susan V
authors.initials: SV
authors.lastname: Duff
authors.affiliation: Northwestern University, Chicago, IL, USA.
authors.forename: Jiaxiu
authors.initials: J
authors.lastname: He
authors.affiliation: University of Southern California, Los Angeles, CA, USA.
authors.forename: Monica A
authors.initials: MA
authors.lastname: Nelsen
authors.affiliation: University of Southern California, Los Angeles, CA, USA.
authors.forename: Christianne J
authors.initials: CJ
authors.lastname: Lane
authors.affiliation: University of Central Arkansas, Conway, AR, USA Texas Woman's University, Dallas, TX, USA.
authors.forename: Veronica T
authors.initials: VT
authors.lastname: Rowe
authors.affiliation: Emory School of Medicine, Atlanta, GA, USA.
authors.forename: Steve L
authors.initials: SL
authors.lastname: Wolf
authors.affiliation: Georgetown University and MedStar National Rehabilitation Hospital, Washington, DC, USA.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Dromerick
authors.affiliation: University of Southern California, Los Angeles, CA, USA winstein@usc.edu.
authors.forename: Carolee J
authors.initials: CJ
authors.lastname: Winstein
mesh_terms: D001132:Arm / Q000503:physiopathology*; D017326:Clinical Trials, Phase III as Topic; D004185:Disability Evaluation; D001330:Electronic Data Processing; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D015337:Multicenter Studies as Topic; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D000071939:Stroke Rehabilitation; D013997:Time Factors
keywords: assessment; impairment; motor control; observational; quality; stroke