02876nas a2200313   4500008004100000020002200041245010100063210006900164250001500233260000800248300001200256490000700268520179500275653005102070653002002121653003702141653002602178653001902204653001102223653003002234653004602264653003502310653002802345653001302373100002102386700001702407700001502424856012302439       2007                        eng d  a0315-162X (Print)00aImproving patient reported outcomes using item response theory and computerized adaptive testing0 aImproving patient reported outcomes using item response theory a  a2007/06/07  cJun  a1426-310 v343 aOBJECTIVE: Patient reported outcomes (PRO) are considered central outcome measures for both clinical trials and observational studies in rheumatology. More sophisticated statistical models, including item response theory (IRT) and computerized adaptive testing (CAT), will enable critical evaluation and reconstruction of currently utilized PRO instruments to improve measurement precision while reducing item burden on the individual patient. METHODS: We developed a domain hierarchy encompassing the latent trait of physical function/disability from the more general to most specific. Items collected from 165 English-language instruments were evaluated by a structured process including trained raters, modified Delphi expert consensus, and then patient evaluation. Each item in the refined data bank will undergo extensive analysis using IRT to evaluate response functions and measurement precision. CAT will allow for real-time questionnaires of potentially smaller numbers of questions tailored directly to each individual's level of physical function. RESULTS: Physical function/disability domain comprises 4 subdomains: upper extremity, trunk, lower extremity, and complex activities. Expert and patient review led to consensus favoring use of present-tense "capability" questions using a 4- or 5-item Likert response construct over past-tense "performance"items. Floor and ceiling effects, attribution of disability, and standardization of response categories were also addressed. CONCLUSION: By applying statistical techniques of IRT through use of CAT, existing PRO instruments may be improved to reduce questionnaire burden on the individual patients while increasing measurement precision that may ultimately lead to reduced sample size requirements for costly clinical trials.10a*Rheumatic Diseases/physiopathology/psychology10aClinical Trials10aData Interpretation, Statistical10aDisability Evaluation10aHealth Surveys10aHumans10aInternational Cooperation10aOutcome Assessment (Health Care)/*methods10aPatient Participation/*methods10aResearch Design/*trends10aSoftware1 aChakravarty, E F1 aBjorner, J B1 aFries, J F  uhttp://mail.iacat.org/content/improving-patient-reported-outcomes-using-item-response-theory-and-computerized-adaptive01915nas a2200157   4500008004100000245010500041210006900146300001000215490000700225520132900232653003401561100001501595700001301610700001301623856012101636       2005                        eng d00aThe promise of PROMIS: using item response theory to improve assessment of patient-reported outcomes0 apromise of PROMIS using item response theory to improve assessme  aS53-70 v233 aPROMIS (Patient-Reported-Outcomes Measurement Information System) is an NIH Roadmap network project intended to improve the reliability, validity, and precision of PROs and to provide definitive new instruments that will exceed the capabilities of classic instruments and enable improved outcome measurement for clinical research across all NIH institutes. Item response theory (IRT) measurement models now permit us to transition conventional health status assessment into an era of item banking and computerized adaptive testing (CAT). Item banking uses IRT measurement models and methods to develop item banks from large pools of items from many available questionnaires. IRT allows the reduction and improvement of items and assembles domains of items which are unidimensional and not excessively redundant. CAT provides a model-driven algorithm and software to iteratively select the most informative remaining item in a domain until a desired degree of precision is obtained. Through these approaches the number of patients required for a clinical trial may be reduced while holding statistical power constant. PROMIS tools, expected to improve precision and enable assessment at the individual patient level which should broaden the appeal of PROs, will begin to be available to the general medical community in 2008.10acomputerized adaptive testing1 aFries, J F1 aBruce, B1 aCella, D  uhttp://mail.iacat.org/content/promise-promis-using-item-response-theory-improve-assessment-patient-reported-outcomes