Introduction to Item Response Theory and Computerized Adaptive Testing for Outcomes Measurement Instruments (Part II)
*Karon Cook, University of Washington 
*Laura Lee Johnson, NIH 
*Irene Katzan, Cleveland Clinic and The MetroHealth System 
*Nan Rothrock, Northwestern University Feinberg School of Medicine 

Keywords: computerized adaptive testing (CAT), item response theory (IRT), patient reported outcomes (PRO)

Research studies and clinicians increasingly collect self-reported health measures. However, the development and interpretation of the measurements are often overlooked. Many new patient reported outcome (PRO) instruments use modern measurement theory, offering advantages in instrument creation and application. Attendees will become familiar with basic item response theory (IRT) terminology, what it is, how it works, and how IRT compares to classical test theory. Speakers also will discuss the fundamentals of computer adaptive testing (CAT) and what is required to create and administer CAT. Key points and the challenges and opportunities for using PRO instruments in health policy research will be illustrated with examples.