Rasch Measurement of Patient -reported Communicative Functioning: Initial Development of an Item Bank

Despite the importance of functional outcome data in determining healthcare utilization policy, “communicative functioning” as a construct is poorly defined and rarely reported in evaluating treatment outcomes in aphasia. Rasch analysis and item banking are psychometric methods that have been applied to health outcomes assessment, and have the potential to improve measurement of communicative functioning. Items banks, a prerequisite for adaptive testing, are groups of questions demonstrated to measure a single construct and calibrated to a common metric. In this paper, the utility of Rasch models in defining communicative functioning and improving its measurement will be demonstrated using patient-reported data.