@article {185,
	title = {Simulated computerized adaptive tests for measuring functional status were efficient with good discriminant validity in patients with hip, knee, or foot/ankle impairments},
	journal = {Journal of Clinical Epidemiology},
	volume = {58},
	number = {6},
	year = {2005},
	note = {0895-4356 (Print)Journal ArticleMulticenter StudyValidation Studies},
	pages = {629-38},
	abstract = {BACKGROUND AND OBJECTIVE: To develop computerized adaptive tests (CATs) designed to assess lower extremity functional status (FS) in people with lower extremity impairments using items from the Lower Extremity Functional Scale and compare discriminant validity of FS measures generated using all items analyzed with a rating scale Item Response Theory model (theta(IRT)) and measures generated using the simulated CATs (theta(CAT)). METHODS: Secondary analysis of retrospective intake rehabilitation data. RESULTS: Unidimensionality of items was strong, and local independence of items was adequate. Differential item functioning (DIF) affected item calibration related to body part, that is, hip, knee, or foot/ankle, but DIF did not affect item calibration for symptom acuity, gender, age, or surgical history. Therefore, patients were separated into three body part specific groups. The rating scale model fit all three data sets well. Three body part specific CATs were developed: each was 70\% more efficient than using all LEFS items to estimate FS measures. theta(IRT) and theta(CAT) measures discriminated patients by symptom acuity, age, and surgical history in similar ways. theta(CAT) measures were as precise as theta(IRT) measures. CONCLUSION: Body part-specific simulated CATs were efficient and produced precise measures of FS with good discriminant validity.},
	keywords = {*Health Status Indicators, Activities of Daily Living, Adolescent, Adult, Aged, Aged, 80 and over, Ankle Joint/physiopathology, Diagnosis, Computer-Assisted/*methods, Female, Hip Joint/physiopathology, Humans, Joint Diseases/physiopathology/*rehabilitation, Knee Joint/physiopathology, Lower Extremity/*physiopathology, Male, Middle Aged, Research Support, N.I.H., Extramural, Research Support, U.S. Gov{\textquoteright}t, P.H.S., Retrospective Studies},
	author = {Hart, D. L. and Mioduski, J. E. and Stratford, P. W.}
}
@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 {87,
	title = {Refining the conceptual basis for rehabilitation outcome measurement: personal care and instrumental activities domain},
	journal = {Medical Care},
	volume = {42},
	number = {1 Suppl},
	year = {2004},
	note = {0025-7079Journal Article},
	month = {Jan},
	pages = {I62-172},
	abstract = {BACKGROUND: Rehabilitation outcome measures routinely include content on performance of daily activities; however, the conceptual basis for item selection is rarely specified. These instruments differ significantly in format, number, and specificity of daily activity items and in the measurement dimensions and type of scale used to specify levels of performance. We propose that a requirement for upper limb and hand skills underlies many activities of daily living (ADL) and instrumental activities of daily living (IADL) items in current instruments, and that items selected based on this definition can be placed along a single functional continuum. OBJECTIVE: To examine the dimensional structure and content coverage of a Personal Care and Instrumental Activities item set and to examine the comparability of items from existing instruments and a set of new items as measures of this domain. METHODS: Participants (N = 477) from 3 different disability groups and 4 settings representing the continuum of postacute rehabilitation care were administered the newly developed Activity Measure for Post-Acute Care (AM-PAC), the SF-8, and an additional setting-specific measure: FIM (in-patient rehabilitation); MDS (skilled nursing facility); MDS-PAC (postacute settings); OASIS (home care); or PF-10 (outpatient clinic). Rasch (partial-credit model) analyses were conducted on a set of 62 items covering the Personal Care and Instrumental domain to examine item fit, item functioning, and category difficulty estimates and unidimensionality. RESULTS: After removing 6 misfitting items, the remaining 56 items fit acceptably along the hypothesized continuum. Analyses yielded different difficulty estimates for the maximum score (eg, "Independent performance") for items with comparable content from different instruments. Items showed little differential item functioning across age, diagnosis, or severity groups, and 92\% of the participants fit the model. CONCLUSIONS: ADL and IADL items from existing rehabilitation outcomes instruments that depend on skilled upper limb and hand use can be located along a single continuum, along with the new personal care and instrumental items of the AM-PAC addressing gaps in content. Results support the validity of the proposed definition of the Personal Care and Instrumental Activities dimension of function as a guide for future development of rehabilitation outcome instruments, such as linked, setting-specific short forms and computerized adaptive testing approaches.},
	keywords = {*Self Efficacy, *Sickness Impact Profile, Activities of Daily Living/*classification/psychology, Adult, Aged, Aged, 80 and over, Disability Evaluation, Factor Analysis, Statistical, Female, Humans, Male, Middle Aged, Outcome Assessment (Health Care)/*methods/statistics \& numerical data, Questionnaires/*standards, Recovery of Function/physiology, Rehabilitation/*standards/statistics \& numerical data, Reproducibility of Results, Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S., Research Support, U.S. Gov{\textquoteright}t, P.H.S., Sensitivity and Specificity},
	author = {Coster, W. J. and Haley, S. M. and Andres, P. L. and Ludlow, L. H. and Bond, T. L. and Ni, P. S.}
}
@article {34,
	title = {Developing an initial physical function item bank from existing sources},
	journal = {Journal of Applied Measurement},
	volume = {4},
	number = {2},
	year = {2003},
	note = {1529-7713Journal Article},
	pages = {124-36},
	abstract = {The objective of this article is to illustrate incremental item banking using health-related quality of life data collected from two samples of patients receiving cancer treatment. The kinds of decisions one faces in establishing an item bank for computerized adaptive testing are also illustrated. Pre-calibration procedures include: identifying common items across databases; creating a new database with data from each pool; reverse-scoring "negative" items; identifying rating scales used in items; identifying pivot points in each rating scale; pivot anchoring items at comparable rating scale categories; and identifying items in each instrument that measure the construct of interest. A series of calibrations were conducted in which a small proportion of new items were added to the common core and misfitting items were identified and deleted until an initial item bank has been developed.},
	keywords = {*Databases, *Sickness Impact Profile, Adaptation, Psychological, Data Collection, Humans, Neoplasms/*physiopathology/psychology/therapy, Psychometrics, Quality of Life/*psychology, Research Support, U.S. Gov{\textquoteright}t, P.H.S., United States},
	author = {Bode, R. K. and Cella, D. and Lai, J. S. and Heinemann, A. W.}
}
@article {238,
	title = {Item banking to improve, shorten and computerized self-reported fatigue: an illustration of steps to create a core item bank from the FACIT-Fatigue Scale},
	journal = {Quality of Life Research},
	volume = {12},
	number = {5},
	year = {2003},
	note = {0962-9343Journal Article},
	month = {Aug},
	pages = {485-501},
	abstract = {Fatigue is a common symptom among cancer patients and the general population. Due to its subjective nature, fatigue has been difficult to effectively and efficiently assess. Modern computerized adaptive testing (CAT) can enable precise assessment of fatigue using a small number of items from a fatigue item bank. CAT enables brief assessment by selecting questions from an item bank that provide the maximum amount of information given a person{\textquoteright}s previous responses. This article illustrates steps to prepare such an item bank, using 13 items from the Functional Assessment of Chronic Illness Therapy Fatigue Subscale (FACIT-F) as the basis. Samples included 1022 cancer patients and 1010 people from the general population. An Item Response Theory (IRT)-based rating scale model, a polytomous extension of the Rasch dichotomous model was utilized. Nine items demonstrating acceptable psychometric properties were selected and positioned on the fatigue continuum. The fatigue levels measured by these nine items along with their response categories covered 66.8\% of the general population and 82.6\% of the cancer patients. Although the operational CAT algorithms to handle polytomously scored items are still in progress, we illustrated how CAT may work by using nine core items to measure level of fatigue. Using this illustration, a fatigue measure comparable to its full-length 13-item scale administration was obtained using four items. The resulting item bank can serve as a core to which will be added a psychometrically sound and operational item bank covering the entire fatigue continuum.},
	keywords = {*Health Status Indicators, *Questionnaires, Adult, Fatigue/*diagnosis/etiology, Female, Humans, Male, Middle Aged, Neoplasms/complications, Psychometrics, Research Support, Non-U.S. Gov{\textquoteright}t, Research Support, U.S. Gov{\textquoteright}t, P.H.S., Sickness Impact Profile},
	author = {Lai, J-S. and Crane, P. K. and Cella, D. and Chang, C-H. and Bode, R. K. and Heinemann, A. W.}
}
@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.}
}
