@article {147,
	title = {Computerized adaptive measurement of depression: A simulation study},
	journal = {BMC Psychiatry},
	volume = {4},
	number = {1},
	year = {2004},
	pages = {13-23},
	abstract = {Background: Efficient, accurate instruments for measuring depression are increasingly importantin clinical practice. We developed a computerized adaptive version of the Beck DepressionInventory (BDI). We examined its efficiency and its usefulness in identifying Major DepressiveEpisodes (MDE) and in measuring depression severity.Methods: Subjects were 744 participants in research studies in which each subject completed boththe BDI and the SCID. In addition, 285 patients completed the Hamilton Depression Rating Scale.Results: The adaptive BDI had an AUC as an indicator of a SCID diagnosis of MDE of 88\%,equivalent to the full BDI. The adaptive BDI asked fewer questions than the full BDI (5.6 versus 21items). The adaptive latent depression score correlated r = .92 with the BDI total score and thelatent depression score correlated more highly with the Hamilton (r = .74) than the BDI total scoredid (r = .70).Conclusions: Adaptive testing for depression may provide greatly increased efficiency withoutloss of accuracy in identifying MDE or in measuring depression severity.},
	keywords = {*Computer Simulation, Adult, Algorithms, Area Under Curve, Comparative Study, Depressive Disorder/*diagnosis/epidemiology/psychology, Diagnosis, Computer-Assisted/*methods/statistics \& numerical data, Factor Analysis, Statistical, Female, Humans, Internet, Male, Mass Screening/methods, Patient Selection, Personality Inventory/*statistics \& numerical data, Pilot Projects, Prevalence, Psychiatric Status Rating Scales/*statistics \& numerical data, Psychometrics, Research Support, Non-U.S. Gov{\textquoteright}t, Research Support, U.S. Gov{\textquoteright}t, P.H.S., Severity of Illness Index, Software},
	author = {Gardner, W. and Shear, K. and Kelleher, K. J. and Pajer, K. A. and Mammen, O. and Buysse, D. and Frank, E.}
}
@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 {31,
	title = {The feasibility of applying item response theory to measures of migraine impact: a re-analysis of three clinical studies},
	journal = {Quality of Life Research},
	volume = {12},
	number = {8},
	year = {2003},
	note = {0962-9343Journal Article},
	pages = {887-902},
	abstract = {BACKGROUND: Item response theory (IRT) is a powerful framework for analyzing multiitem scales and is central to the implementation of computerized adaptive testing. OBJECTIVES: To explain the use of IRT to examine measurement properties and to apply IRT to a questionnaire for measuring migraine impact--the Migraine Specific Questionnaire (MSQ). METHODS: Data from three clinical studies that employed the MSQ-version 1 were analyzed by confirmatory factor analysis for categorical data and by IRT modeling. RESULTS: Confirmatory factor analyses showed very high correlations between the factors hypothesized by the original test constructions. Further, high item loadings on one common factor suggest that migraine impact may be adequately assessed by only one score. IRT analyses of the MSQ were feasible and provided several suggestions as to how to improve the items and in particular the response choices. Out of 15 items, 13 showed adequate fit to the IRT model. In general, IRT scores were strongly associated with the scores proposed by the original test developers and with the total item sum score. Analysis of response consistency showed that more than 90\% of the patients answered consistently according to a unidimensional IRT model. For the remaining patients, scores on the dimension of emotional function were less strongly related to the overall IRT scores that mainly reflected role limitations. Such response patterns can be detected easily using response consistency indices. Analysis of test precision across score levels revealed that the MSQ was most precise at one standard deviation worse than the mean impact level for migraine patients that are not in treatment. Thus, gains in test precision can be achieved by developing items aimed at less severe levels of migraine impact. CONCLUSIONS: IRT proved useful for analyzing the MSQ. The approach warrants further testing in a more comprehensive item pool for headache impact that would enable computerized adaptive testing.},
	keywords = {*Sickness Impact Profile, Adolescent, Adult, Aged, Comparative Study, Cost of Illness, Factor Analysis, Statistical, Feasibility Studies, Female, Human, Male, Middle Aged, Migraine/*psychology, Models, Psychological, Psychometrics/instrumentation/*methods, Quality of Life/*psychology, Questionnaires, Support, Non-U.S. Gov{\textquoteright}t},
	author = {Bjorner, J. B. and Kosinski, M. and Ware, J. E., Jr.}
}
@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.}
}
@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.}
}
