title: Work-related measures of physical and behavioral health function: Test-retest reliability.
abstract: BACKGROUND
  The Work Disability Functional Assessment Battery (WD-FAB), developed for potential use by the US Social Security Administration to assess work-related function, currently consists of five multi-item scales assessing physical function and four multi-item scales assessing behavioral health function; the WD-FAB scales are administered as Computerized Adaptive Tests (CATs).
  
  
  OBJECTIVE
  The goal of this study was to evaluate the test-retest reliability of the WD-FAB Physical Function and Behavioral Health CATs.
  
  
  METHODS
  We administered the WD-FAB scales twice, 7-10 days apart, to a sample of 376 working age adults and 316 adults with work-disability. Intraclass correlation coefficients were calculated to measure the consistency of the scores between the two administrations. Standard error of measurement (SEM) and minimal detectable change (MDC90) were also calculated to measure the scales precision and sensitivity.
  
  
  RESULTS
  For the Physical Function CAT scales, the ICCs ranged from 0.76 to 0.89 in the working age adult sample, and 0.77-0.86 in the sample of adults with work-disability. ICCs for the Behavioral Health CAT scales ranged from 0.66 to 0.70 in the working age adult sample, and 0.77-0.80 in the adults with work-disability. The SEM ranged from 3.25 to 4.55 for the Physical Function scales and 5.27-6.97 for the Behavioral Health function scales. For all scales in both samples, the MDC90 ranged from 7.58 to 16.27.
  
  
  CONCLUSIONS
  Both the Physical Function and Behavioral Health CATs of the WD-FAB demonstrated good test-retest reliability in adults with work-disability and general adult samples, a critical requirement for assessing work related functioning in disability applicants and in other contexts.
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA. Electronic address: memarino@bu.edu.
authors.forename: Molly Elizabeth
authors.initials: ME
authors.lastname: Marino
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA; VA Boston Healthcare System, Center for Healthcare Organization and Implementation Research, Boston, MA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Meterko
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA.
authors.forename: Elizabeth E
authors.initials: EE
authors.lastname: Marfeo
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: McDonough
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jette
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA.
authors.forename: Pengsheng
authors.initials: P
authors.lastname: Ni
authors.affiliation: Boston University School of Public Health, Health & Disability Research Institute, 715 Albany Street, T5W, Boston MA 02118, USA.
authors.forename: Kara
authors.initials: K
authors.lastname: Bogusz
authors.affiliation: National Institutes of Health, Rehabilitation Medicine Department, Mark O. Hatfield Clinical Research Center, Bethesda, MD, USA.
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: Rasch
authors.affiliation: National Institutes of Health, Rehabilitation Medicine Department, Mark O. Hatfield Clinical Research Center, Bethesda, MD, USA.
authors.forename: Diane E
authors.initials: DE
authors.lastname: Brandt
authors.affiliation: National Institutes of Health, Rehabilitation Medicine Department, Mark O. Hatfield Clinical Research Center, Bethesda, MD, USA.
authors.forename: Leighton
authors.initials: L
authors.lastname: Chan
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014481:United States; D019131:United States Social Security Administration; D014937:Work; D014938:Work Capacity Evaluation; D055815:Young Adult
keywords: Computer-adaptive test; Disability evaluation; Psychometrics; Reliability; United States Social Security Administration