James F. Fries
Publication Details
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Progress in assessing physical function in arthritis: PROMIS short forms and computerized adaptive testing.
J Rheumatol. 2009; (9): 2061-6
Assessing self-reported physical function/disability with the Health Assessment Questionnaire Disability Index (HAQ) and other instruments has become central in arthritis research. Item response theory (IRT) and computerized adaptive testing (CAT) techniques can increase reliability and statistical power. IRT-based instruments can improve measurement precision substantially over a wider range of disease severity. These modern methods were applied and the magnitude of improvement was estimated.
