Advantages in Using Item Response Theory in Developing Outcome Measures in Rehabilitation: Reliability, Patient Burden, and Differential Item Functioning 9639

With the advancement in technology and modern psychometric methodology, Item Response Theory (IRT) has been applied to the development of outcome assessments that enable computer-adaptive testing (CAT). While researchers and clinicians are typically trained to assess functional outcomes using fixed-length measures based on classic test theory, they have shown a growing interest in understanding why and how IRT can be used to develop outcome measures with good reliability and minimized test burden. This symposium aims at providing rehabilitation professionals a better understanding of the advantages of using item response theory versus clinical test theory in developing outcome measures, including reduced test burden, floor and ceiling effect, and practice effect, demonstrated by two practical examples – the PROMIS physical function and the NIH Toolbox Visual Reasoning Test. A better knowledge of this will help rehabilitation professionals make informed decisions when selecting reliable measures practical for use in research and practice