@article {143,
	title = {Progress in assessing physical function in arthritis: PROMIS short forms and computerized adaptive testing},
	journal = {Journal of Rheumatology},
	volume = {36},
	number = {9},
	year = {2009},
	note = {Fries, James FCella, DavidRose, MatthiasKrishnan, EswarBruce, BonnieU01 AR052158/AR/NIAMS NIH HHS/United StatesU01 AR52177/AR/NIAMS NIH HHS/United StatesConsensus Development ConferenceResearch Support, N.I.H., ExtramuralCanadaThe Journal of rheumatologyJ Rheumatol. 2009 Sep;36(9):2061-6.},
	month = {Sep},
	pages = {2061-2066},
	edition = {2009/09/10},
	abstract = {OBJECTIVE: 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.},
	keywords = {*Disability Evaluation, *Outcome Assessment (Health Care), Arthritis/diagnosis/*physiopathology, Health Surveys, Humans, Prognosis, Reproducibility of Results},
	isbn = {0315-162X (Print)0315-162X (Linking)},
	author = {Fries, J.F. and Cella, D. and Rose, M. and Krishnan, E. and Bruce, B.}
}
@article {52,
	title = {Improving patient reported outcomes using item response theory and computerized adaptive testing},
	journal = {Journal of Rheumatology},
	volume = {34},
	number = {6},
	year = {2007},
	note = {Chakravarty, Eliza FBjorner, Jakob BFries, James FAr052158/ar/niamsConsensus Development ConferenceResearch Support, N.I.H., ExtramuralCanadaThe Journal of rheumatologyJ Rheumatol. 2007 Jun;34(6):1426-31.},
	month = {Jun},
	pages = {1426-31},
	edition = {2007/06/07},
	abstract = {OBJECTIVE: 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{\textquoteright}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.},
	keywords = {*Rheumatic Diseases/physiopathology/psychology, Clinical Trials, Data Interpretation, Statistical, Disability Evaluation, Health Surveys, Humans, International Cooperation, Outcome Assessment (Health Care)/*methods, Patient Participation/*methods, Research Design/*trends, Software},
	isbn = {0315-162X (Print)},
	author = {Chakravarty, E. F. and Bjorner, J. B. and Fries, J.F.}
}
@article {51,
	title = {The Patient-Reported Outcomes Measurement Information System (PROMIS): progress of an NIH Roadmap cooperative group during its first two years},
	journal = {Medical Care},
	volume = {45},
	number = {5 Suppl 1},
	year = {2007},
	pages = {S3-S11},
	abstract = {The National Institutes of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS) Roadmap initiative (www.nihpromis.org) is a 5-year cooperative group program of research designed to develop, validate, and standardize item banks to measure patient-reported outcomes (PROs) relevant across common medical conditions. In this article, we will summarize the organization and scientific activity of the PROMIS network during its first 2 years.},
	author = {Cella, D. and Yount, S. and Rothrock, N. and Gershon, R. C. and Cook, K. F. and Reeve, B. and Ader, D. and Fries, J.F. and Bruce, B. and Rose, M.}
}
@article {142,
	title = {The promise of PROMIS: using item response theory to improve assessment of patient-reported outcomes},
	journal = {Clinical and Experimental Rheumatology},
	volume = {23},
	number = {5 Suppl 39},
	year = {2005},
	pages = {S53-7},
	abstract = {PROMIS (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.},
	keywords = {computerized adaptive testing},
	author = {Fries, J.F. and Bruce, B. and Cella, D.}
}
