%0 Journal Article %J Journal of Clinical Epidemiology %D 2005 %T Simulated computerized adaptive tests for measuring functional status were efficient with good discriminant validity in patients with hip, knee, or foot/ankle impairments %A Hart, D. L. %A Mioduski, J. E. %A Stratford, P. W. %K *Health Status Indicators %K Activities of Daily Living %K Adolescent %K Adult %K Aged %K Aged, 80 and over %K Ankle Joint/physiopathology %K Diagnosis, Computer-Assisted/*methods %K Female %K Hip Joint/physiopathology %K Humans %K Joint Diseases/physiopathology/*rehabilitation %K Knee Joint/physiopathology %K Lower Extremity/*physiopathology %K Male %K Middle Aged %K Research Support, N.I.H., Extramural %K Research Support, U.S. Gov't, P.H.S. %K Retrospective Studies %X 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. %B Journal of Clinical Epidemiology %V 58 %P 629-38 %G eng %M 15878477 %0 Journal Article %J Archives of Physical Medicine and Rehabilitation %D 2002 %T Development of an index of physical functional health status in rehabilitation %A Hart, D. L. %A Wright, B. D. %K *Health Status Indicators %K *Rehabilitation Centers %K Adolescent %K Adult %K Aged %K Aged, 80 and over %K Female %K Health Surveys %K Humans %K Male %K Middle Aged %K Musculoskeletal Diseases/*physiopathology/*rehabilitation %K Nervous System Diseases/*physiopathology/*rehabilitation %K Physical Fitness/*physiology %K Recovery of Function/physiology %K Reproducibility of Results %K Retrospective Studies %X OBJECTIVE: To describe (1) the development of an index of physical functional health status (FHS) and (2) its hierarchical structure, unidimensionality, reproducibility of item calibrations, and practical application. DESIGN: Rasch analysis of existing data sets. SETTING: A total of 715 acute, orthopedic outpatient centers and 62 long-term care facilities in 41 states participating with Focus On Therapeutic Outcomes, Inc. PATIENTS: A convenience sample of 92,343 patients (40% male; mean age +/- standard deviation [SD], 48+/-17y; range, 14-99y) seeking rehabilitation between 1993 and 1999. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients completed self-report health status surveys at admission and discharge. The Medical Outcomes Study 36-Item Short-Form Health Survey's physical functioning scale (PF-10) is the foundation of the physical FHS. The Oswestry Low Back Pain Disability Questionnaire, Neck Disability Index, Lysholm Knee Questionnaire, items pertinent to patients with upper-extremity impairments, and items pertinent to patients with more involved neuromusculoskeletal impairments were cocalibrated into the PF-10. RESULTS: The final FHS item bank contained 36 items (patient separation, 2.3; root mean square measurement error, 5.9; mean square +/- SD infit, 0.9+/-0.5; outfit, 0.9+/-0.9). Analyses supported empirical item hierarchy, unidimensionality, reproducibility of item calibrations, and content and construct validity of the FHS-36. CONCLUSIONS: Results support the reliability and validity of FHS-36 measures in the present sample. Analyses show the potential for a dynamic, computer-controlled, adaptive survey for FHS assessment applicable for group analysis and clinical decision making for individual patients. %B Archives of Physical Medicine and Rehabilitation %V 83 %P 655-65 %8 May %G eng %M 11994805