@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 {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.} }