Urea cycle disorders (UCDs) comprise deficiencies in any of the six enzymes and two transport proteins involved in urea biosynthesis. The specific disorders are: n-acetylglutamate synthase deficiency, ...

Purpose Assessing health-related quality of life (HRQoL) via Computerized Adaptive Tests (CAT) provides greater measurement precision coupled with a lower test burden compared to conventional tests.

In a previous simulation study of methods for assessing differential item functioning (DIF) in computer-adaptive tests (Zwick, Thayer, & Wingersky, 1993, 1994), modified versions of the ...

Intellectual disability causes significant limitations to a person’s intellectual functioning and adaptive behavior. Intellectual disability is also sometimes known as cognitive disability. An ...