%0 Journal Article %J Journal of Applied Measurement %D 2006 %T Expansion of a physical function item bank and development of an abbreviated form for clinical research %A Bode, R. K. %A Lai, J-S. %A Dineen, K. %A Heinemann, A. W. %A Shevrin, D. %A Von Roenn, J. %A Cella, D. %K clinical research %K computerized adaptive testing %K performance levels %K physical function item bank %K Psychometrics %K test reliability %K Test Validity %X We expanded an existing 33-item physical function (PF) item bank with a sufficient number of items to enable computerized adaptive testing (CAT). Ten items were written to expand the bank and the new item pool was administered to 295 people with cancer. For this analysis of the new pool, seven poorly performing items were identified for further examination. This resulted in a bank with items that define an essentially unidimensional PF construct, cover a wide range of that construct, reliably measure the PF of persons with cancer, and distinguish differences in self-reported functional performance levels. We also developed a 5-item (static) assessment form ("BriefPF") that can be used in clinical research to express scores on the same metric as the overall bank. The BriefPF was compared to the PF-10 from the Medical Outcomes Study SF-36. Both short forms significantly differentiated persons across functional performance levels. While the entire bank was more precise across the PF continuum than either short form, there were differences in the area of the continuum in which each short form was more precise: the BriefPF was more precise than the PF-10 at the lower functional levels and the PF-10 was more precise than the BriefPF at the higher levels. Future research on this bank will include the development of a CAT version, the PF-CAT. (PsycINFO Database Record (c) 2007 APA, all rights reserved) %B Journal of Applied Measurement %I Richard M Smith: US %V 7 %P 1-15 %@ 1529-7713 (Print) %G eng %M 2006-01262-001 %0 Journal Article %J Quality of Life Research %D 2006 %T Factor analysis techniques for assessing sufficient unidimensionality of cancer related fatigue %A Lai, J-S. %A Crane, P. K. %A Cella, D. %K *Factor Analysis, Statistical %K *Quality of Life %K Aged %K Chicago %K Fatigue/*etiology %K Female %K Humans %K Male %K Middle Aged %K Neoplasms/*complications %K Questionnaires %X 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. %B Quality of Life Research %V 15 %P 1179-90 %8 Sep %G eng %M 17001438 %0 Journal Article %J Journal of Pain and Symptom Management %D 2005 %T An item response theory-based pain item bank can enhance measurement precision %A Lai, J-S. %A Dineen, K. %A Reeve, B. B. %A Von Roenn, J. %A Shervin, D. %A McGuire, M. %A Bode, R. K. %A Paice, J. %A Cella, D. %K computerized adaptive testing %X Cancer-related pain is often under-recognized and undertreated. This is partly due to the lack of appropriate assessments, which need to be comprehensive and precise yet easily integrated into clinics. Computerized adaptive testing (CAT) can enable precise-yet-brief assessments by only selecting the most informative items from a calibrated item bank. The purpose of this study was to create such a bank. The sample included 400 cancer patients who were asked to complete 61 pain-related items. Data were analyzed using factor analysis and the Rasch model. The final bank consisted of 43 items which satisfied the measurement requirement of factor analysis and the Rasch model, demonstrated high internal consistency and reasonable item-total correlations, and discriminated patients with differing degrees of pain. We conclude that this bank demonstrates good psychometric properties, is sensitive to pain reported by patients, and can be used as the foundation for a CAT pain-testing platform for use in clinical practice. %B Journal of Pain and Symptom Management %V 30 %P 278-88 %G eng %M 16183012