title: The Aphasia Communication Outcome Measure (ACOM): Dimensionality, Item Bank Calibration, and Initial Validation.
abstract: OBJECTIVE
  The purpose of this study is to investigate the structure and measurement properties of the Aphasia Communication Outcome Measure (ACOM), a patient-reported outcome measure of communicative functioning for persons with aphasia.
  
  
  METHODS
  Three hundred twenty-nine participants with aphasia responded to 177 items asking about communicative functioning. The data were analyzed using a categorical item factor analysis approach. Validity of ACOM scores on the basis of their convergence with performance-based, clinician-reported, and surrogate-reported assessments of communication was also assessed.
  
  
  RESULTS
  Fifty-nine items that obtained adequate fit to a modified bifactor measurement model and functioned similarly across several demographic and clinical subgroupings were identified. The factor model estimates were transformed to item response theory graded response model parameters, and the resulting score estimates showed good precision and moderately strong convergence with other measures of communicative ability and functioning. A free software application for administration and scoring of the ACOM item bank is available from the first author.
  
  
  CONCLUSIONS
  The ACOM provides reliable measurement of patient-reported communicative functioning in aphasia. The results supported the validity of ACOM scores insofar as (a) factor analyses provided support for a coherent measurement model, (b) items functioned similarly across demographic and clinical subgroups, and (c) scores showed good convergence with measures of related constructs.
authors: William D
authors: WD
authors: Hula
authors: Patrick J
authors: PJ
authors: Doyle
authors: Clement A
authors: CA
authors: Stone
authors: Shannon N
authors: SN
authors: Austermann Hula
authors: Stacey
authors: S
authors: Kellough
authors: Julie L
authors: JL
authors: Wambaugh
authors: Katherine B
authors: KB
authors: Ross
authors: James G
authors: JG
authors: Schumacher
authors: Ann
authors: A
authors: St Jacque
mesh_terms: D001037:Aphasia / Q000175:diagnosis* / Q000209:etiology; D002138:Calibration; D003142:Communication; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D033181:Information Dissemination; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D015203:Reproducibility of Results; D057566:Self Report; D012984:Software; D020521:Stroke / Q000150:complications / Q000175:diagnosis