@article {186, title = {Computerized adaptive testing for patients with knee inpairments produced valid and responsive measures of function}, journal = {Journal of Clinical Epidemiology}, volume = {61}, number = {4}, year = {2008}, pages = {1113-1124}, author = {Hart, D. L. and Wang, Y-C. and Stratford, P. W. and Mioduski, J. E.} } @article {2073, title = {Simulated computerized adaptive test for patients with lumbar spine impairments was efficient and produced valid measures of function}, journal = {Journal of Clinical Epidemiology}, volume = {59}, year = {2006}, pages = {947{\textendash}956}, abstract = {Objective: To equate physical functioning (PF) items with Back Pain Functional Scale (BPFS) items, develop a computerized adaptive test (CAT) designed to assess lumbar spine functional status (LFS) in people with lumbar spine impairments, and compare discriminant validity of LFS measures (qIRT) generated using all items analyzed with a rating scale Item Response Theory model (RSM) and measures generated using the simulated CAT (qCAT). Methods: We performed a secondary analysis of retrospective intake rehabilitation data. Results: Unidimensionality and local independence of 25 BPFS and PF items were supported. Differential item functioning was negligible for levels of symptom acuity, gender, age, and surgical history. The RSM fit the data well. A lumbar spine specific CAT was developed that was 72\% more efficient than using all 25 items to estimate LFS measures. qIRT and qCAT measures did not discriminate patients by symptom acuity, age, or gender, but discriminated patients by surgical history in similar clinically logical ways. qCAT measures were as precise as qIRT measures. Conclusion: A body part specific simulated CAT developed from an LFS item bank was efficient and produced precise measures of LFS without eroding discriminant validity.}, keywords = {Back Pain Functional Scale, computerized adaptive testing, Item Response Theory, Lumbar spine, Rehabilitation, True-score equating}, doi = {10.1016/j.jclinepi.2005.10.017}, author = {Hart, D. L. and Mioduski, J. E. and Werneke, M. W. and Stratford, P. W.} } @article {184, title = {Simulated computerized adaptive test for patients with shoulder impairments was efficient and produced valid measures of function}, journal = {Journal of Clinical Epidemiology}, volume = {59}, number = {3}, year = {2006}, note = {0895-4356 (Print)Journal ArticleValidation Studies}, pages = {290-8}, abstract = {BACKGROUND AND OBJECTIVE: To test unidimensionality and local independence of a set of shoulder functional status (SFS) items, develop a computerized adaptive test (CAT) of the items using a rating scale item response theory model (RSM), and compare discriminant validity of measures generated using all items (theta(IRT)) and measures generated using the simulated CAT (theta(CAT)). STUDY DESIGN AND SETTING: We performed a secondary analysis of data collected prospectively during rehabilitation of 400 patients with shoulder impairments who completed 60 SFS items. RESULTS: Factor analytic techniques supported that the 42 SFS items formed a unidimensional scale and were locally independent. Except for five items, which were deleted, the RSM fit the data well. The remaining 37 SFS items were used to generate the CAT. On average, 6 items were needed to estimate precise measures of function using the SFS CAT, compared with all 37 SFS items. The theta(IRT) and theta(CAT) measures were highly correlated (r = .96) and resulted in similar classifications of patients. CONCLUSION: The simulated SFS CAT was efficient and produced precise, clinically relevant measures of functional status with good discriminating ability.}, keywords = {*Computer Simulation, *Range of Motion, Articular, Activities of Daily Living, Adult, Aged, Aged, 80 and over, Factor Analysis, Statistical, Female, Humans, Male, Middle Aged, Prospective Studies, Reproducibility of Results, Research Support, N.I.H., Extramural, Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S., Shoulder Dislocation/*physiopathology/psychology/rehabilitation, Shoulder Pain/*physiopathology/psychology/rehabilitation, Shoulder/*physiopathology, Sickness Impact Profile, Treatment Outcome}, author = {Hart, D. L. and Cook, K. F. and Mioduski, J. E. and Teal, C. R. and Crane, P. K.} } @article {2074, title = {Simulated computerized adaptive test for patients with shoulder impairments was efficient and produced valid measures of function}, journal = {Journal of Clinical Epidemiology}, volume = {59}, year = {2006}, pages = {290-298}, abstract = {

Background and Objective: To test unidimensionality and local independence of a set of shoulder functional status (SFS) items,
develop a computerized adaptive test (CAT) of the items using a rating scale item response theory model (RSM), and compare discriminant validity of measures generated using all items (qIRT) and measures generated using the simulated CAT (qCAT).
Study Design and Setting: We performed a secondary analysis of data collected prospectively during rehabilitation of 400 patients
with shoulder impairments who completed 60 SFS items.
Results: Factor analytic techniques supported that the 42 SFS items formed a unidimensional scale and were locally independent. Except for five items, which were deleted, the RSM fit the data well. The remaining 37 SFS items were used to generate the CAT. On average, 6 items on were needed to estimate precise measures of function using the SFS CAT, compared with all 37 SFS items. The qIRT and qCAT measures were highly correlated (r 5 .96) and resulted in similar classifications of patients.
Conclusion: The simulated SFS CAT was efficient and produced precise, clinically relevant measures of functional status with good
discriminating ability.\ 

}, keywords = {computerized adaptive testing, Flexilevel Scale of Shoulder Function, Item Response Theory, Rehabilitation}, author = {Hart, D. L. and Cook, K. F. and Mioduski, J. E. and Teal, C. R. and Crane, P. K.} } @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.} }