@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.}
}
@booklet {200,
	title = {Practical methods for dealing with {\textquoteright}not applicable{\textquoteright} item responses in the AMC Linear Disability Score project},
	journal = {Health and Quality of Life Outcomes},
	volume = {2},
	year = {2004},
	note = {Holman, RebeccaGlas, Cees A WLindeboom, RobertZwinderman, Aeilko Hde Haan, Rob JEnglandHealth Qual Life Outcomes. 2004 Jun 16;2:29.},
	month = {Jun 16},
	pages = {29},
	type = {Comparative StudyResearch Support, Non-U.S. Gov{\textquoteright}t},
	edition = {2004/06/18},
	abstract = {BACKGROUND: Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a {\textquoteright}not applicable{\textquoteright} category to items included in the AMC Linear Disability Score (ALDS) project item bank. METHODS: The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the {\textquoteright}tendency to respond to items{\textquoteright}. RESULTS: The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the {\textquoteright}tendency to respond to items{\textquoteright}. The estimates obtained using the cold deck imputation method were substantially different. CONCLUSIONS: The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used.},
	keywords = {*Disability Evaluation, *Health Surveys, *Logistic Models, *Questionnaires, Activities of Daily Living/*classification, Data Interpretation, Statistical, Health Status, Humans, Pilot Projects, Probability, Quality of Life, Severity of Illness Index},
	isbn = {1477-7525 (Electronic)1477-7525 (Linking)},
	author = {Holman, R. and Glas, C. A. and Lindeboom, R. and Zwinderman, A. H. and de Haan, R. J.}
}
