Table 1.
Clinical and socio-demographic characteristics of participants in piloting and validation phases.
Table 2.
Rasch fit statistics, item measure and DIF contrasts for the 35-item 4-point response VQoL-CYP instrument.
Items are ordered by item measure (logits) from positive (items harder to endorse) to negative (items easier to endorse).
Fig 1.
Category probability curves for 4 response categories, with a distinct peak for each category (1 = not at all, 2 = a little bit, 3 = quite a lot and 4 = exactly).
Fig 2.
Person-item map illustrating targeting of items to participants.
Items are located on the right of the dashed line. Participants are located on the left side of the dashed line and represented by X. Children with lower ‘ability’ and ‘less difficult’ items are at the bottom half of the map. M = Mean, S = 1 standard deviation from the mean, T = 2 standard deviations from the mean.
Table 3.
Pearson coefficients for correlations across the outcome measures.