@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 {86,
	title = {IRT health outcomes data analysis project: an overview and summary},
	journal = {Quality of Life Research},
	volume = {16},
	number = {Suppl. 1},
	year = {2007},
	note = {Cook, Karon FTeal, Cayla RBjorner, Jakob BCella, DavidChang, Chih-HungCrane, Paul KGibbons, Laura EHays, Ron DMcHorney, Colleen AOcepek-Welikson, KatjaRaczek, Anastasia ETeresi, Jeanne AReeve, Bryce B1U01AR52171-01/AR/United States NIAMSR01 (CA60068)/CA/United States NCIY1-PC-3028-01/PC/United States NCIResearch Support, N.I.H., ExtramuralNetherlandsQuality of life research : an international journal of quality of life aspects of treatment, care and rehabilitationQual Life Res. 2007;16 Suppl 1:121-32. Epub 2007 Mar 10.},
	pages = {121-132},
	edition = {2007/03/14},
	abstract = {BACKGROUND: In June 2004, the National Cancer Institute and the Drug Information Association co-sponsored the conference, "Improving the Measurement of Health Outcomes through the Applications of Item Response Theory (IRT) Modeling: Exploration of Item Banks and Computer-Adaptive Assessment." A component of the conference was presentation of a psychometric and content analysis of a secondary dataset. OBJECTIVES: A thorough psychometric and content analysis was conducted of two primary domains within a cancer health-related quality of life (HRQOL) dataset. RESEARCH DESIGN: HRQOL scales were evaluated using factor analysis for categorical data, IRT modeling, and differential item functioning analyses. In addition, computerized adaptive administration of HRQOL item banks was simulated, and various IRT models were applied and compared. SUBJECTS: The original data were collected as part of the NCI-funded Quality of Life Evaluation in Oncology (Q-Score) Project. A total of 1,714 patients with cancer or HIV/AIDS were recruited from 5 clinical sites. MEASURES: Items from 4 HRQOL instruments were evaluated: Cancer Rehabilitation Evaluation System-Short Form, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Functional Assessment of Cancer Therapy and Medical Outcomes Study Short-Form Health Survey. RESULTS AND CONCLUSIONS: Four lessons learned from the project are discussed: the importance of good developmental item banks, the ambiguity of model fit results, the limits of our knowledge regarding the practical implications of model misfit, and the importance in the measurement of HRQOL of construct definition. With respect to these lessons, areas for future research are suggested. The feasibility of developing item banks for broad definitions of health is discussed.},
	keywords = {*Data Interpretation, Statistical, *Health Status, *Quality of Life, *Questionnaires, *Software, Female, HIV Infections/psychology, Humans, Male, Neoplasms/psychology, Outcome Assessment (Health Care)/*methods, Psychometrics, Stress, Psychological},
	isbn = {0962-9343 (Print)},
	author = {Cook, K. F. and Teal, C. R. and Bjorner, J. B. and Cella, D. and Chang, C-H. and Crane, P. K. and Gibbons, L. E. and Hays, R. D. and McHorney, C. A. and Ocepek-Welikson, K. and Raczek, A. E. and Teresi, J. A. and Reeve, B. B.}
}
@article {328,
	title = {Psychometric evaluation and calibration of health-related quality of life item banks: plans for the Patient-Reported Outcomes Measurement Information System (PROMIS)},
	journal = {Medical Care},
	volume = {45},
	number = {5 Suppl 1},
	year = {2007},
	note = {Reeve, Bryce BHays, Ron DBjorner, Jakob BCook, Karon FCrane, Paul KTeresi, Jeanne AThissen, DavidRevicki, Dennis AWeiss, David JHambleton, Ronald KLiu, HonghuGershon, RichardReise, Steven PLai, Jin-sheiCella, DavidPROMIS Cooperative GroupAG015815/AG/United States NIAResearch Support, N.I.H., ExtramuralUnited StatesMedical careMed Care. 2007 May;45(5 Suppl 1):S22-31.},
	month = {May},
	pages = {S22-31},
	edition = {2007/04/20},
	abstract = {BACKGROUND: The construction and evaluation of item banks to measure unidimensional constructs of health-related quality of life (HRQOL) is a fundamental objective of the Patient-Reported Outcomes Measurement Information System (PROMIS) project. OBJECTIVES: Item banks will be used as the foundation for developing short-form instruments and enabling computerized adaptive testing. The PROMIS Steering Committee selected 5 HRQOL domains for initial focus: physical functioning, fatigue, pain, emotional distress, and social role participation. This report provides an overview of the methods used in the PROMIS item analyses and proposed calibration of item banks. ANALYSES: Analyses include evaluation of data quality (eg, logic and range checking, spread of response distribution within an item), descriptive statistics (eg, frequencies, means), item response theory model assumptions (unidimensionality, local independence, monotonicity), model fit, differential item functioning, and item calibration for banking. RECOMMENDATIONS: Summarized are key analytic issues; recommendations are provided for future evaluations of item banks in HRQOL assessment.},
	keywords = {*Health Status, *Information Systems, *Quality of Life, *Self Disclosure, Adolescent, Adult, Aged, Calibration, Databases as Topic, Evaluation Studies as Topic, Female, Humans, Male, Middle Aged, Outcome Assessment (Health Care)/*methods, Psychometrics, Questionnaires/standards, United States},
	isbn = {0025-7079 (Print)},
	author = {Reeve, B. B. and Hays, R. D. and Bjorner, J. B. and Cook, K. F. and Crane, P. K. and Teresi, J. A. and Thissen, D. and Revicki, D. A. and Weiss,  D. J. and Hambleton, R. K. and Liu, H. and Gershon, R. C. and Reise, S. P. and Lai, J. S. and Cella, D.}
}
@article {237,
	title = {Factor analysis techniques for assessing sufficient unidimensionality of cancer related fatigue},
	journal = {Quality of Life Research},
	volume = {15},
	number = {7},
	year = {2006},
	note = {0962-9343 (Print)Journal ArticleResearch Support, N.I.H., Extramural},
	month = {Sep},
	pages = {1179-90},
	abstract = {BACKGROUND: Fatigue is the most common unrelieved symptom experienced by people with cancer. The purpose of this study was to examine whether cancer-related fatigue (CRF) can be summarized using a single score, that is, whether CRF is sufficiently unidimensional for measurement approaches that require or assume unidimensionality. We evaluated this question using factor analysis techniques including the theory-driven bi-factor model. METHODS: Five hundred and fifty five cancer patients from the Chicago metropolitan area completed a 72-item fatigue item bank, covering a range of fatigue-related concerns including intensity, frequency and interference with physical, mental, and social activities. Dimensionality was assessed using exploratory and confirmatory factor analysis (CFA) techniques. RESULTS: Exploratory factor analysis (EFA) techniques identified from 1 to 17 factors. The bi-factor model suggested that CRF was sufficiently unidimensional. CONCLUSIONS: CRF can be considered sufficiently unidimensional for applications that require unidimensionality. One such application, item response theory (IRT), will facilitate the development of short-form and computer-adaptive testing. This may further enable practical and accurate clinical assessment of CRF.},
	keywords = {*Factor Analysis, Statistical, *Quality of Life, Aged, Chicago, Fatigue/*etiology, Female, Humans, Male, Middle Aged, Neoplasms/*complications, Questionnaires},
	author = {Lai, J-S. and Crane, P. K. and Cella, D.}
}
@article {121,
	title = {Data pooling and analysis to build a preliminary item bank: an example using bowel function in prostate cancer},
	journal = {Evaluation and the Health Professions},
	volume = {28},
	number = {2},
	year = {2005},
	note = {0163-2787 (Print)Journal Article},
	pages = {142-59},
	abstract = {Assessing bowel function (BF) in prostate cancer can help determine therapeutic trade-offs. We determined the components of BF commonly assessed in prostate cancer studies as an initial step in creating an item bank for clinical and research application. We analyzed six archived data sets representing 4,246 men with prostate cancer. Thirty-one items from validated instruments were available for analysis. Items were classified into domains (diarrhea, rectal urgency, pain, bleeding, bother/distress, and other) then subjected to conventional psychometric and item response theory (IRT) analyses. Items fit the IRT model if the ratio between observed and expected item variance was between 0.60 and 1.40. Four of 31 items had inadequate fit in at least one analysis. Poorly fitting items included bleeding (2), rectal urgency (1), and bother/distress (1). A fifth item assessing hemorrhoids was poorly correlated with other items. Our analyses supported four related components of BF: diarrhea, rectal urgency, pain, and bother/distress.},
	keywords = {*Quality of Life, *Questionnaires, Adult, Aged, Data Collection/methods, Humans, Intestine, Large/*physiopathology, Male, Middle Aged, Prostatic Neoplasms/*physiopathology, Psychometrics, Research Support, Non-U.S. Gov{\textquoteright}t, Statistics, Nonparametric},
	author = {Eton, D. T. and Lai, J. S. and Cella, D. and Reeve, B. B. and Talcott, J. A. and Clark, J. A. and McPherson, C. P. and Litwin, M. S. and Moinpour, C. M.}
}
@article {236,
	title = {An item bank was created to improve the measurement of cancer-related fatigue},
	journal = {Journal of Clinical Epidemiology},
	volume = {58},
	number = {2},
	year = {2005},
	note = {Lai, Jin-SheiCella, DavidDineen, KellyBode, RitaVon Roenn, JamieGershon, Richard CShevrin, DanielEnglandJ Clin Epidemiol. 2005 Feb;58(2):190-7.},
	month = {Feb},
	pages = {190-7},
	type = {Multicenter Study},
	edition = {2005/02/01},
	abstract = {OBJECTIVE: Cancer-related fatigue (CRF) is one of the most common unrelieved symptoms experienced by patients. CRF is underrecognized and undertreated due to a lack of clinically sensitive instruments that integrate easily into clinics. Modern computerized adaptive testing (CAT) can overcome these obstacles by enabling precise assessment of fatigue without requiring the administration of a large number of questions. A working item bank is essential for development of a CAT platform. The present report describes the building of an operational item bank for use in clinical settings with the ultimate goal of improving CRF identification and treatment. STUDY DESIGN AND SETTING: The sample included 301 cancer patients. Psychometric properties of items were examined by using Rasch analysis, an Item Response Theory (IRT) model. RESULTS AND CONCLUSION: The final bank includes 72 items. These 72 unidimensional items explained 57.5\% of the variance, based on factor analysis results. Excellent internal consistency (alpha=0.99) and acceptable item-total correlation were found (range: 0.51-0.85). The 72 items covered a reasonable range of the fatigue continuum. No significant ceiling effects, floor effects, or gaps were found. A sample short form was created for demonstration purposes. The resulting bank is amenable to the development of a CAT platform.},
	keywords = {Adult, Aged, Aged, 80 and over, Factor Analysis, Statistical, Fatigue/*etiology/psychology, Female, Humans, Male, Middle Aged, Neoplasms/*complications/psychology, Psychometrics, Questionnaires},
	isbn = {0895-4356 (Print)0895-4356 (Linking)},
	author = {Lai, J-S. and Cella, D. and Dineen, K. and Bode, R. and Von Roenn, J. and Gershon, R. C. and Shevrin, D.}
}
@article {34,
	title = {Developing an initial physical function item bank from existing sources},
	journal = {Journal of Applied Measurement},
	volume = {4},
	number = {2},
	year = {2003},
	note = {1529-7713Journal Article},
	pages = {124-36},
	abstract = {The objective of this article is to illustrate incremental item banking using health-related quality of life data collected from two samples of patients receiving cancer treatment. The kinds of decisions one faces in establishing an item bank for computerized adaptive testing are also illustrated. Pre-calibration procedures include: identifying common items across databases; creating a new database with data from each pool; reverse-scoring "negative" items; identifying rating scales used in items; identifying pivot points in each rating scale; pivot anchoring items at comparable rating scale categories; and identifying items in each instrument that measure the construct of interest. A series of calibrations were conducted in which a small proportion of new items were added to the common core and misfitting items were identified and deleted until an initial item bank has been developed.},
	keywords = {*Databases, *Sickness Impact Profile, Adaptation, Psychological, Data Collection, Humans, Neoplasms/*physiopathology/psychology/therapy, Psychometrics, Quality of Life/*psychology, Research Support, U.S. Gov{\textquoteright}t, P.H.S., United States},
	author = {Bode, R. K. and Cella, D. and Lai, J. S. and Heinemann, A. W.}
}
@article {238,
	title = {Item banking to improve, shorten and computerized self-reported fatigue: an illustration of steps to create a core item bank from the FACIT-Fatigue Scale},
	journal = {Quality of Life Research},
	volume = {12},
	number = {5},
	year = {2003},
	note = {0962-9343Journal Article},
	month = {Aug},
	pages = {485-501},
	abstract = {Fatigue is a common symptom among cancer patients and the general population. Due to its subjective nature, fatigue has been difficult to effectively and efficiently assess. Modern computerized adaptive testing (CAT) can enable precise assessment of fatigue using a small number of items from a fatigue item bank. CAT enables brief assessment by selecting questions from an item bank that provide the maximum amount of information given a person{\textquoteright}s previous responses. This article illustrates steps to prepare such an item bank, using 13 items from the Functional Assessment of Chronic Illness Therapy Fatigue Subscale (FACIT-F) as the basis. Samples included 1022 cancer patients and 1010 people from the general population. An Item Response Theory (IRT)-based rating scale model, a polytomous extension of the Rasch dichotomous model was utilized. Nine items demonstrating acceptable psychometric properties were selected and positioned on the fatigue continuum. The fatigue levels measured by these nine items along with their response categories covered 66.8\% of the general population and 82.6\% of the cancer patients. Although the operational CAT algorithms to handle polytomously scored items are still in progress, we illustrated how CAT may work by using nine core items to measure level of fatigue. Using this illustration, a fatigue measure comparable to its full-length 13-item scale administration was obtained using four items. The resulting item bank can serve as a core to which will be added a psychometrically sound and operational item bank covering the entire fatigue continuum.},
	keywords = {*Health Status Indicators, *Questionnaires, Adult, Fatigue/*diagnosis/etiology, Female, Humans, Male, Middle Aged, Neoplasms/complications, Psychometrics, Research Support, Non-U.S. Gov{\textquoteright}t, Research Support, U.S. Gov{\textquoteright}t, P.H.S., Sickness Impact Profile},
	author = {Lai, J-S. and Crane, P. K. and Cella, D. and Chang, C-H. and Bode, R. K. and Heinemann, A. W.}
}
@article {48,
	title = {Advances in quality of life measurements in oncology patients},
	journal = {Seminars in Oncology},
	volume = {29},
	number = {3 Suppl 8},
	year = {2002},
	note = {0093-7754 (Print)Journal ArticleReview},
	month = {Jun},
	pages = {60-8},
	abstract = {Accurate assessment of the quality of life (QOL) of patients can provide important clinical information to physicians, especially in the area of oncology. Changes in QOL are important indicators of the impact of a new cytotoxic therapy, can affect a patient{\textquoteright}s willingness to continue treatment, and may aid in defining response in the absence of quantifiable endpoints such as tumor regression. Because QOL is becoming an increasingly important aspect in the management of patients with malignant disease, it is vital that the instruments used to measure QOL are reliable and accurate. Assessment of QOL involves a multidimensional approach that includes physical, functional, social, and emotional well-being, and the most comprehensive instruments measure at least three of these domains. Instruments to measure QOL can be generic (eg, the Nottingham Health Profile), targeted toward specific illnesses (eg, Functional Assessment of Cancer Therapy - Lung), or be a combination of generic and targeted. Two of the most widely used examples of the combination, or hybrid, instruments are the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 Items and the Functional Assessment of Chronic Illness Therapy. A consequence of the increasing international collaboration in clinical trials has been the growing necessity for instruments that are valid across languages and cultures. To assure the continuing reliability and validity of QOL instruments in this regard, item response theory can be applied. Techniques such as item response theory may be used in the future to construct QOL item banks containing large sets of validated questions that represent various levels of QOL domains. As QOL becomes increasingly important in understanding and approaching the overall management of cancer patients, the tools available to clinicians and researchers to assess QOL will continue to evolve. While the instruments currently available provide reliable and valid measurement, further improvements in precision and application are anticipated.},
	keywords = {*Quality of Life, *Sickness Impact Profile, Cross-Cultural Comparison, Culture, Humans, Language, Neoplasms/*physiopathology, Questionnaires},
	author = {Cella, D. and Chang, C-H. and Lai, J. S. and Webster, K.}
}
@article {50,
	title = {Measuring quality of life in chronic illness: the functional assessment of chronic illness therapy measurement system},
	journal = {Archives of Physical Medicine and Rehabilitation},
	volume = {83},
	number = {12 Suppl 2},
	year = {2002},
	note = {0003-9993Journal Article},
	month = {Dec},
	pages = {S10-7},
	abstract = {We focus on quality of life (QOL) measurement as applied to chronic illness. There are 2 major types of health-related quality of life (HRQOL) instruments-generic health status and targeted. Generic instruments offer the opportunity to compare results across patient and population cohorts, and some can provide normative or benchmark data from which to interpret results. Targeted instruments ask questions that focus more on the specific condition or treatment under study and, as a result, tend to be more responsive to clinically important changes than generic instruments. Each type of instrument has a place in the assessment of HRQOL in chronic illness, and consideration of the relative advantages and disadvantages of the 2 options best drives choice of instrument. The Functional Assessment of Chronic Illness Therapy (FACIT) system of HRQOL measurement is a hybrid of the 2 approaches. The FACIT system combines a core general measure with supplemental measures targeted toward specific diseases, conditions, or treatments. Thus, it capitalizes on the strengths of each type of measure. Recently, FACIT questionnaires were administered to a representative sample of the general population with results used to derive FACIT norms. These normative data can be used for benchmarking and to better understand changes in HRQOL that are often seen in clinical trials. Future directions in HRQOL assessment include test equating, item banking, and computerized adaptive testing.},
	keywords = {*Chronic Disease, *Quality of Life, *Rehabilitation, Adult, Comparative Study, Health Status Indicators, Humans, Psychometrics, Questionnaires, Research Support, U.S. Gov{\textquoteright}t, P.H.S., Sensitivity and Specificity},
	author = {Cella, D. and Nowinski, C. J.}
}
