@booklet {154,
	title = {Cross-cultural development of an item list for computer-adaptive testing of fatigue in oncological patients},
	journal = {Health and Quality of Life Outcomes},
	volume = {9},
	number = {1},
	year = {2011},
	note = {Health Qual Life Outcomes. 2011 Mar 29;9(1):19.},
	month = {March 29, 2011},
	pages = {10},
	edition = {2011/03/31},
	abstract = {ABSTRACT: INTRODUCTION: Within an ongoing project of the EORTC Quality of Life Group, we are developing computerized adaptive test (CAT) measures for the QLQ-C30 scales. These new CAT measures are conceptualised to reflect the same constructs as the QLQ-C30 scales. Accordingly, the Fatigue-CAT is intended to capture physical and general fatigue. METHODS: The EORTC approach to CAT development comprises four phases (literature search, operationalisation, pre-testing, and field testing). Phases I-III are described in detail in this paper. A literature search for fatigue items was performed in major medical databases. After refinement through several expert panels, the remaining items were used as the basis for adapting items and/or formulating new items fitting the EORTC item style. To obtain feedback from patients with cancer, these English items were translated into Danish, French, German, and Spanish and tested in the respective countries. RESULTS: Based on the literature search a list containing 588 items was generated. After a comprehensive item selection procedure focusing on content, redundancy, item clarity and item difficulty a list of 44 fatigue items was generated. Patient interviews (n=52) resulted in 12 revisions of wording and translations. DISCUSSION: The item list developed in phases I-III will be further investigated within a field-testing phase (IV) to examine psychometric characteristics and to fit an item response theory model. The Fatigue CAT based on this item bank will provide scores that are backward-compatible to the original QLQ-C30 fatigue scale.},
	isbn = {1477-7525 (Electronic)1477-7525 (Linking)},
	author = {Giesinger, J. M. and Petersen, M. A. and Groenvold, M. and Aaronson, N. K. and Arraras, J. I. and Conroy, T. and Gamper, E. M. and Kemmler, G. and King, M. T. and Oberguggenberger, A. S. and Velikova, G. and Young, T. and Holzner, B. and Eortc-Qlg, E. O.}
}
@article {312,
	title = {Development of computerized adaptive testing (CAT) for the EORTC QLQ-C30 physical functioning dimension},
	journal = {Quality of Life Research },
	volume = {20},
	number = {4},
	year = {2010},
	note = {Qual Life Res. 2010 Oct 23.},
	pages = {479-490},
	edition = {2010/10/26},
	abstract = {PURPOSE: Computerized adaptive test (CAT) methods, based on item response theory (IRT), enable a patient-reported outcome instrument to be adapted to the individual patient while maintaining direct comparability of scores. The EORTC Quality of Life Group is developing a CAT version of the widely used EORTC QLQ-C30. We present the development and psychometric validation of the item pool for the first of the scales, physical functioning (PF). METHODS: Initial developments (including literature search and patient and expert evaluations) resulted in 56 candidate items. Responses to these items were collected from 1,176 patients with cancer from Denmark, France, Germany, Italy, Taiwan, and the United Kingdom. The items were evaluated with regard to psychometric properties. RESULTS: Evaluations showed that 31 of the items could be included in a unidimensional IRT model with acceptable fit and good content coverage, although the pool may lack items at the upper extreme (good PF). There were several findings of significant differential item functioning (DIF). However, the DIF findings appeared to have little impact on the PF estimation. CONCLUSIONS: We have established an item pool for CAT measurement of PF and believe that this CAT instrument will clearly improve the EORTC measurement of PF.},
	isbn = {1573-2649 (Electronic)0962-9343 (Linking)},
	author = {Petersen, M. A. and Groenvold, M. and Aaronson, N. K. and Chie, W. C. and Conroy, T. and Costantini, A. and Fayers, P. and Helbostad, J. and Holzner, B. and Kaasa, S. and Singer, S. and Velikova, G. and Young, T.}
}
@article {311,
	title = {Multidimensional computerized adaptive testing of the EORTC QLQ-C30: basic developments and evaluations},
	journal = {Quality of Life Research},
	volume = {15},
	number = {3},
	year = {2006},
	note = {Petersen, Morten AaGroenvold, MogensAaronson, NeilFayers, PeterSprangers, MirjamBjorner, Jakob BEuropean Organisation for Research and Treatment of Cancer Quality of Life GroupResearch Support, Non-U.S. Gov{\textquoteright}tNetherlandsQuality of life research : an international journal of quality of life aspects of treatment, care and rehabilitationQual Life Res. 2006 Apr;15(3):315-29.},
	month = {Apr},
	pages = {315-29},
	edition = {2006/03/21},
	abstract = {OBJECTIVE: Self-report questionnaires are widely used to measure health-related quality of life (HRQOL). Ideally, such questionnaires should be adapted to the individual patient and at the same time scores should be directly comparable across patients. This may be achieved using computerized adaptive testing (CAT). Usually, CAT is carried out for a single domain at a time. However, many HRQOL domains are highly correlated. Multidimensional CAT may utilize these correlations to improve measurement efficiency. We investigated the possible advantages and difficulties of multidimensional CAT. STUDY DESIGN AND SETTING: We evaluated multidimensional CAT of three scales from the EORTC QLQ-C30: the physical functioning, emotional functioning, and fatigue scales. Analyses utilised a database with 2958 European cancer patients. RESULTS: It was possible to obtain scores for the three domains with five to seven items administered using multidimensional CAT that were very close to the scores obtained using all 12 items and with no or little loss of measurement precision. CONCLUSION: The findings suggest that multidimensional CAT may significantly improve measurement precision and efficiency and encourage further research into multidimensional CAT. Particularly, the estimation of the model underlying the multidimensional CAT and the conceptual aspects need further investigations.},
	keywords = {*Quality of Life, *Self Disclosure, Adult, Female, Health Status, Humans, Male, Middle Aged, Questionnaires/*standards, User-Computer Interface},
	isbn = {0962-9343 (Print)},
	author = {Petersen, M. A. and Groenvold, M. and Aaronson, N. K. and Fayers, P. and Sprangers, M. and Bjorner, J. B.}
}
