Figure 3.

Test information curves for the VFS-Peds, including the VFS-P (mental and physical domains), the VFS-C, and the VFS-T. Dashed horizontal line represents the minimum acceptable test information level (i.e., test information = 11.1). IRT = item response theory; VFS-C = VFS child self-report scale; VFS-P = VFS parent proxy–report scale; VFS-Peds = pediatric versions of the Vanderbilt Fatigue Scale; VFS-T = VFS teacher proxy–report scale.