@article {384,
	title = {Overview of quantitative measurement methods. Equivalence, invariance, and differential item functioning in health applications},
	journal = {Medical Care},
	volume = {44},
	number = {11 Suppl 3},
	year = {2006},
	note = {Teresi, Jeanne AAG15294/AG/NIA NIH HHS/United StatesResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov{\textquoteright}tReviewUnited StatesMedical careMed Care. 2006 Nov;44(11 Suppl 3):S39-49.},
	month = {Nov},
	pages = {S39-49},
	edition = {2006/10/25},
	abstract = {BACKGROUND: Reviewed in this article are issues relating to the study of invariance and differential item functioning (DIF). The aim of factor analyses and DIF, in the context of invariance testing, is the examination of group differences in item response conditional on an estimate of disability. Discussed are parameters and statistics that are not invariant and cannot be compared validly in crosscultural studies with varying distributions of disability in contrast to those that can be compared (if the model assumptions are met) because they are produced by models such as linear and nonlinear regression. OBJECTIVES: The purpose of this overview is to provide an integrated approach to the quantitative methods used in this special issue to examine measurement equivalence. The methods include classical test theory (CTT), factor analytic, and parametric and nonparametric approaches to DIF detection. Also included in the quantitative section is a discussion of item banking and computerized adaptive testing (CAT). METHODS: Factorial invariance and the articles discussing this topic are introduced. A brief overview of the DIF methods presented in the quantitative section of the special issue is provided together with a discussion of ways in which DIF analyses and examination of invariance using factor models may be complementary. CONCLUSIONS: Although factor analytic and DIF detection methods share features, they provide unique information and can be viewed as complementary in informing about measurement equivalence.},
	keywords = {*Cross-Cultural Comparison, Data Interpretation, Statistical, Factor Analysis, Statistical, Guidelines as Topic, Humans, Models, Statistical, Psychometrics/*methods, Statistics as Topic/*methods, Statistics, Nonparametric},
	isbn = {0025-7079 (Print)0025-7079 (Linking)},
	author = {Teresi, J. A.}
}
@article {30,
	title = {Calibration of an item pool for assessing the burden of headaches: an application of item response theory to the Headache Impact Test (HIT)},
	journal = {Quality of Life Research},
	volume = {12},
	number = {8},
	year = {2003},
	note = {0962-9343Journal Article},
	pages = {913-933},
	abstract = {BACKGROUND: Measurement of headache impact is important in clinical trials, case detection, and the clinical monitoring of patients. Computerized adaptive testing (CAT) of headache impact has potential advantages over traditional fixed-length tests in terms of precision, relevance, real-time quality control and flexibility. OBJECTIVE: To develop an item pool that can be used for a computerized adaptive test of headache impact. METHODS: We analyzed responses to four well-known tests of headache impact from a population-based sample of recent headache sufferers (n = 1016). We used confirmatory factor analysis for categorical data and analyses based on item response theory (IRT). RESULTS: In factor analyses, we found very high correlations between the factors hypothesized by the original test constructers, both within and between the original questionnaires. These results suggest that a single score of headache impact is sufficient. We established a pool of 47 items which fitted the generalized partial credit IRT model. By simulating a computerized adaptive health test we showed that an adaptive test of only five items had a very high concordance with the score based on all items and that different worst-case item selection scenarios did not lead to bias. CONCLUSION: We have established a headache impact item pool that can be used in CAT of headache impact.},
	keywords = {*Cost of Illness, *Decision Support Techniques, *Sickness Impact Profile, Adolescent, Adult, Aged, Comparative Study, Disability Evaluation, Factor Analysis, Statistical, Headache/*psychology, Health Surveys, Human, Longitudinal Studies, Middle Aged, Migraine/psychology, Models, Psychological, Psychometrics/*methods, Quality of Life/*psychology, Software, Support, Non-U.S. Gov{\textquoteright}t},
	author = {Bjorner, J. B. and Kosinski, M. and Ware, J. E., Jr.}
}
@article {234,
	title = {Evaluating the usefulness of computerized adaptive testing for medical in-course assessment},
	journal = {Academic Medicine},
	volume = {74},
	number = {10},
	year = {1999},
	note = {Kreiter, C DFerguson, KGruppen, L DUnited statesAcademic medicine : journal of the Association of American Medical CollegesAcad Med. 1999 Oct;74(10):1125-8.},
	month = {Oct},
	pages = {1125-8},
	edition = {1999/10/28},
	abstract = {PURPOSE: This study investigated the feasibility of converting an existing computer-administered, in-course internal medicine test to an adaptive format. METHOD: A 200-item internal medicine extended matching test was used for this research. Parameters were estimated with commercially available software with responses from 621 examinees. A specially developed simulation program was used to retrospectively estimate the efficiency of the computer-adaptive exam format. RESULTS: It was found that the average test length could be shortened by almost half with measurement precision approximately equal to that of the full 200-item paper-and-pencil test. However, computer-adaptive testing with this item bank provided little advantage for examinees at the upper end of the ability continuum. An examination of classical item statistics and IRT item statistics suggested that adding more difficult items might extend the advantage to this group of examinees. CONCLUSIONS: Medical item banks presently used for incourse assessment might be advantageously employed in adaptive testing. However, it is important to evaluate the match between the items and the measurement objective of the test before implementing this format.},
	keywords = {*Automation, *Education, Medical, Undergraduate, Educational Measurement/*methods, Humans, Internal Medicine/*education, Likelihood Functions, Psychometrics/*methods, Reproducibility of Results},
	isbn = {1040-2446 (Print)},
	author = {Kreiter, C. D. and Ferguson, K. and Gruppen, L. D.}
}
@article {177,
	title = {The effect of item pool restriction on the precision of ability measurement for a Rasch-based CAT: comparisons to traditional fixed length examinations},
	journal = {J Outcome Meas},
	volume = {2},
	number = {2},
	year = {1998},
	note = {983263801090-655xJournal Article},
	pages = {97-122},
	abstract = {This paper describes a method for examining the precision of a computerized adaptive test with a limited item pool. Standard errors of measurement ascertained in the testing of simulees with a CAT using a restricted pool were compared to the results obtained in a live paper-and-pencil achievement testing of 4494 nursing students on four versions of an examination of calculations of drug administration. CAT measures of precision were considered when the simulated examine pools were uniform and normal. Precision indices were also considered in terms of the number of CAT items required to reach the precision of the traditional tests. Results suggest that regardless of the size of the item pool, CAT provides greater precision in measurement with a smaller number of items administered even when the choice of items is limited but fails to achieve equiprecision along the entire ability continuum.},
	keywords = {*Decision Making, Computer-Assisted, Comparative Study, Computer Simulation, Education, Nursing, Educational Measurement/*methods, Human, Models, Statistical, Psychometrics/*methods},
	author = {Halkitis, P. N.}
}
@article {331,
	title = {Health status assessment for the twenty-first century: item response theory, item banking and computer adaptive testing},
	journal = {Quality of Life Research},
	volume = {6},
	number = {6},
	year = {1997},
	note = {Revicki, D ACella, D FEnglandQuality of life research : an international journal of quality of life aspects of treatment, care and rehabilitationQual Life Res. 1997 Aug;6(6):595-600.},
	month = {Aug},
	pages = {595-600},
	edition = {1997/08/01},
	abstract = {Health status assessment is frequently used to evaluate the combined impact of human immunodeficiency virus (HIV) disease and its treatment on functioning and well-being from the patient{\textquoteright}s perspective. No single health status measure can efficiently cover the range of problems in functioning and well-being experienced across HIV disease stages. Item response theory (IRT), item banking and computer adaptive testing (CAT) provide a solution to measuring health-related quality of life (HRQoL) across different stages of HIV disease. IRT allows us to examine the response characteristics of individual items and the relationship between responses to individual items and the responses to each other item in a domain. With information on the response characteristics of a large number of items covering a HRQoL domain (e.g. physical function, and psychological well-being), and information on the interrelationships between all pairs of these items and the total scale, we can construct more efficient scales. Item banks consist of large sets of questions representing various levels of a HRQoL domain that can be used to develop brief, efficient scales for measuring the domain. CAT is the application of IRT and item banks to the tailored assessment of HRQoL domains specific to individual patients. Given the results of IRT analyses and computer-assisted test administration, more efficient and brief scales can be used to measure multiple domains of HRQoL for clinical trials and longitudinal observational studies.},
	keywords = {*Health Status, *HIV Infections/diagnosis, *Quality of Life, Diagnosis, Computer-Assisted, Disease Progression, Humans, Psychometrics/*methods},
	isbn = {0962-9343 (Print)},
	author = {Revicki, D. A. and Cella, D. F.}
}
