02904nas a2200289   4500008004100000020004100041245011100082210006900193250001500262260000800277300001400285490000700299520193300306653002702239653003802266653004102304653001902345653001102364653001402375653003102389100001502420700001302435700001202448700001602460700001302476856012502489       2009                        eng d  a0315-162X (Print)0315-162X (Linking)00aProgress in assessing physical function in arthritis: PROMIS short forms and computerized adaptive testing0 aProgress in assessing physical function in arthritis PROMIS shor  a2009/09/10  cSep  a2061-20660 v363 aOBJECTIVE: Assessing self-reported physical function/disability with the Health Assessment Questionnaire Disability Index (HAQ) and other instruments has become central in arthritis research. Item response theory (IRT) and computerized adaptive testing (CAT) techniques can increase reliability and statistical power. IRT-based instruments can improve measurement precision substantially over a wider range of disease severity. These modern methods were applied and the magnitude of improvement was estimated. METHODS: A 199-item physical function/disability item bank was developed by distilling 1865 items to 124, including Legacy Health Assessment Questionnaire (HAQ) and Physical Function-10 items, and improving precision through qualitative and quantitative evaluation in over 21,000 subjects, which included about 1500 patients with rheumatoid arthritis and osteoarthritis. Four new instruments, (A) Patient-Reported Outcomes Measurement Information (PROMIS) HAQ, which evolved from the original (Legacy) HAQ; (B) "best" PROMIS 10; (C) 20-item static (short) forms; and (D) simulated PROMIS CAT, which sequentially selected the most informative item, were compared with the HAQ. RESULTS: Online and mailed administration modes yielded similar item and domain scores. The HAQ and PROMIS HAQ 20-item scales yielded greater information content versus other scales in patients with more severe disease. The "best" PROMIS 20-item scale outperformed the other 20-item static forms over a broad range of 4 standard deviations. The 10-item simulated PROMIS CAT outperformed all other forms. CONCLUSION: Improved items and instruments yielded better information. The PROMIS HAQ is currently available and considered validated. The new PROMIS short forms, after validation, are likely to represent further improvement. CAT-based physical function/disability assessment offers superior performance over static forms of equal length.10a*Disability Evaluation10a*Outcome Assessment (Health Care)10aArthritis/diagnosis/*physiopathology10aHealth Surveys10aHumans10aPrognosis10aReproducibility of Results1 aFries, J F1 aCella, D1 aRose, M1 aKrishnan, E1 aBruce, B  uhttp://www.iacat.org/content/progress-assessing-physical-function-arthritis-promis-short-forms-and-computerized-adaptive02875nas a2200313   4500008004100000020002200041245010100063210006900164250001500233260000800248300001200256490000700268520179500275653005102070653002002121653003702141653002602178653001902204653001102223653003002234653004602264653003502310653002802345653001302373100002102386700001702407700001502424856012202439       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://www.iacat.org/content/improving-patient-reported-outcomes-using-item-response-theory-and-computerized-adaptive01605nas a2200253   4500008004100000020002200041245003000063210003000093250001500123300001100138490000600149520095200155653001401107653002501121653002901146653001801175653001901193653001101212653001401223653001901237653002001256100001601276856005901292       2005                        eng d  a1529-7713 (Print)00aComputer adaptive testing0 aComputer adaptive testing  a2005/02/11  a109-270 v63 aThe creation of item response theory (IRT) and Rasch models, inexpensive accessibility to high speed desktop computers, and the growth of the Internet, has led to the creation and growth of computerized adaptive testing or CAT. This form of assessment is applicable for both high stakes tests such as certification or licensure exams, as well as health related quality of life surveys. This article discusses the historical background of CAT including its many advantages over conventional (typically paper and pencil) alternatives. The process of CAT is then described including descriptions of the specific differences of using CAT based upon 1-, 2- and 3-parameter IRT and various Rasch models. Numerous specific topics describing CAT in practice are described including: initial item selection, content balancing, test difficulty, test length and stopping rules. The article concludes with the author's reflections regarding the future of CAT.10a*Internet10a*Models, Statistical10a*User-Computer Interface10aCertification10aHealth Surveys10aHumans10aLicensure10aMicrocomputers10aQuality of Life1 aGershon, RC  uhttp://www.iacat.org/content/computer-adaptive-testing02654nas a2200385   4500008004100000245014400041210006900185300001200254490000700266520138100273653002101654653003301675653002901708653001501737653001001752653000901762653002201771653002601793653003301819653002501852653001901877653001001896653002501906653001601931653002401947653002601971653002701997653003202024653001302056653002802069100001702097700001602114700001402130856012402144       2003                        eng d00aCalibration of an item pool for assessing the burden of headaches: an application of item response theory to the Headache Impact Test (HIT)0 aCalibration of an item pool for assessing the burden of headache  a913-9330 v123 aBACKGROUND: Measurement of headache impact is important in clinical trials, case detection, and the clinical monitoring of patients. Computerized adaptive testing (CAT) of headache impact has potential advantages over traditional fixed-length tests in terms of precision, relevance, real-time quality control and flexibility. OBJECTIVE: To develop an item pool that can be used for a computerized adaptive test of headache impact. METHODS: We analyzed responses to four well-known tests of headache impact from a population-based sample of recent headache sufferers (n = 1016). We used confirmatory factor analysis for categorical data and analyses based on item response theory (IRT). RESULTS: In factor analyses, we found very high correlations between the factors hypothesized by the original test constructers, both within and between the original questionnaires. These results suggest that a single score of headache impact is sufficient. We established a pool of 47 items which fitted the generalized partial credit IRT model. By simulating a computerized adaptive health test we showed that an adaptive test of only five items had a very high concordance with the score based on all items and that different worst-case item selection scenarios did not lead to bias. CONCLUSION: We have established a headache impact item pool that can be used in CAT of headache impact.10a*Cost of Illness10a*Decision Support Techniques10a*Sickness Impact Profile10aAdolescent10aAdult10aAged10aComparative Study10aDisability Evaluation10aFactor Analysis, Statistical10aHeadache/*psychology10aHealth Surveys10aHuman10aLongitudinal Studies10aMiddle Aged10aMigraine/psychology10aModels, Psychological10aPsychometrics/*methods10aQuality of Life/*psychology10aSoftware10aSupport, Non-U.S. Gov't1 aBjorner, J B1 aKosinski, M1 aWare, Jr.  uhttp://www.iacat.org/content/calibration-item-pool-assessing-burden-headaches-application-item-response-theory-headache02894nas a2200349   4500008004100000245008300041210006900124260000800193300001100201490000700212520176600219653003001985653002802015653001502043653001002058653000902068653002202077653001102099653001902110653001102129653000902140653001602149653006202165653006102227653003302288653003602321653003102357653002602388100001402414700001602428856010002444       2002                        eng d00aDevelopment of an index of physical functional health status in rehabilitation0 aDevelopment of an index of physical functional health status in   cMay  a655-650 v833 aOBJECTIVE: To describe (1) the development of an index of physical functional health status (FHS) and (2) its hierarchical structure, unidimensionality, reproducibility of item calibrations, and practical application. DESIGN: Rasch analysis of existing data sets. SETTING: A total of 715 acute, orthopedic outpatient centers and 62 long-term care facilities in 41 states participating with Focus On Therapeutic Outcomes, Inc. PATIENTS: A convenience sample of 92,343 patients (40% male; mean age +/- standard deviation [SD], 48+/-17y; range, 14-99y) seeking rehabilitation between 1993 and 1999. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients completed self-report health status surveys at admission and discharge. The Medical Outcomes Study 36-Item Short-Form Health Survey's physical functioning scale (PF-10) is the foundation of the physical FHS. The Oswestry Low Back Pain Disability Questionnaire, Neck Disability Index, Lysholm Knee Questionnaire, items pertinent to patients with upper-extremity impairments, and items pertinent to patients with more involved neuromusculoskeletal impairments were cocalibrated into the PF-10. RESULTS: The final FHS item bank contained 36 items (patient separation, 2.3; root mean square measurement error, 5.9; mean square +/- SD infit, 0.9+/-0.5; outfit, 0.9+/-0.9). Analyses supported empirical item hierarchy, unidimensionality, reproducibility of item calibrations, and content and construct validity of the FHS-36. CONCLUSIONS: Results support the reliability and validity of FHS-36 measures in the present sample. Analyses show the potential for a dynamic, computer-controlled, adaptive survey for FHS assessment applicable for group analysis and clinical decision making for individual patients.10a*Health Status Indicators10a*Rehabilitation Centers10aAdolescent10aAdult10aAged10aAged, 80 and over10aFemale10aHealth Surveys10aHumans10aMale10aMiddle Aged10aMusculoskeletal Diseases/*physiopathology/*rehabilitation10aNervous System Diseases/*physiopathology/*rehabilitation10aPhysical Fitness/*physiology10aRecovery of Function/physiology10aReproducibility of Results10aRetrospective Studies1 aHart, D L1 aWright, B D  uhttp://www.iacat.org/content/development-index-physical-functional-health-status-rehabilitation01774nas a2200289   4500008004100000245007700041210006900118300001400187490000700201520080000208653002501008653003101033653003701064653003801101653001901139653001001158653002701168653004601195653002001241653002801261653003201289653001801321100001401339700001701353700001501370856009901385       2000                        eng d00aItem response theory and health outcomes measurement in the 21st century0 aItem response theory and health outcomes measurement in the 21st  aII28-II420 v383 aItem response theory (IRT) has a number of potential advantages over classical test theory in assessing self-reported health outcomes. IRT models yield invariant item and latent trait estimates (within a linear transformation), standard errors conditional on trait level, and trait estimates anchored to item content. IRT also facilitates evaluation of differential item functioning, inclusion of items with different response formats in the same scale, and assessment of person fit and is ideally suited for implementing computer adaptive testing. Finally, IRT methods can be helpful in developing better health outcome measures and in assessing change over time. These issues are reviewed, along with a discussion of some of the methodological and practical challenges in applying IRT methods.10a*Models, Statistical10aActivities of Daily Living10aData Interpretation, Statistical10aHealth Services Research/*methods10aHealth Surveys10aHuman10aMathematical Computing10aOutcome Assessment (Health Care)/*methods10aResearch Design10aSupport, Non-U.S. Gov't10aSupport, U.S. Gov't, P.H.S.10aUnited States1 aHays, R D1 aMorales, L S1 aReise, S P  uhttp://www.iacat.org/content/item-response-theory-and-health-outcomes-measurement-21st-century