The Aphasia Communication Outcome Measure (ACOM): Dimensionality, Item Bank Calibration, and Initial Validation

Area of Science:

• Neuroscience
• Speech-Language Pathology
• Psychometrics

Background:

• Aphasia significantly impacts communicative functioning.
• Patient-reported outcome measures (PROMs) are crucial for assessing quality of life and functional status in individuals with aphasia.
• The Aphasia Communication Outcome Measure (ACOM) was developed to address this need.

Purpose of the Study:

• To investigate the psychometric properties and measurement structure of the Aphasia Communication Outcome Measure (ACOM).
• To evaluate the ACOM as a patient-reported outcome measure for communicative functioning in persons with aphasia.

Main Methods:

• A cohort of 329 participants with aphasia completed 177 items assessing communicative functioning.
• Categorical item factor analysis was employed to analyze the data.
• Validity was assessed through convergence with performance-based, clinician-reported, and surrogate-reported communication assessments.

Main Results:

• A modified bifactor measurement model identified 59 items with adequate fit and similar functioning across subgroups.
• Item response theory parameters demonstrated good precision for score estimates.
• ACOM scores showed moderately strong convergence with other measures of communicative ability.

Conclusions:

• The ACOM demonstrates reliable measurement of patient-reported communicative functioning in aphasia.
• Factor analyses supported a coherent measurement model for the ACOM.
• ACOM scores are valid, evidenced by consistent item performance across subgroups and convergence with related measures.