Rasch fit statistics, item measure and DIF contrasts for the 35-item 4-point response VQoL-CYP instrument.

<p>Items are ordered by item measure (logits) from positive (items harder to endorse) to negative (items easier to endorse).</p

Person-item map illustrating targeting of items to participants.

<p>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.</p

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).

<p>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).</p

Clinical and socio-demographic characteristics of participants in piloting and validation phases.

<p>Clinical and socio-demographic characteristics of participants in piloting and validation phases.</p

Rose diagrams of the frequency of points plotted along individual meridians for Goldmann and Octopus perimetry for children aged 5–6 years compared to 12–15 years.

<p>A larger area indicates a meridian with a larger number of plotted points. <i>*The empty sectors at 0° for Goldmann perimetry isopters III4e and I4e correspond to the ‘void’ area in the perimeter bowl</i>.</p

Proportion of EBAR (test quality) ratings per perimeter, by age groups.

<p>Proportion of EBAR (test quality) ratings per perimeter, by age groups.</p

Inclusion/exclusion criteria for participants.

<p>Inclusion/exclusion criteria for participants.</p

Association of all hypermetropia and hypermetropia (low or moderate/high), by key socio-demographic factors.

<p>* No qualifications, State school examinations at 16 years of age (‘O’ levels), at 18 years (‘A’ levels) or University/other professional qualification</p><p>⁺: Number of eyes;</p><p>⁺⁺ model adjusted for eye laterality, gender, age (continuous), educational qualification, accommodation tenure, ethnicity and test centre.</p><p>Association of all hypermetropia and hypermetropia (low or moderate/high), by key socio-demographic factors.</p

Demographic, socio-economic and other factors.

<p>Demographic, socio-economic and other factors.</p

Frequency of all myopia and all hypermetropia by age, gender and ethnicity.

<p>Frequency of all myopia and all hypermetropia by age, gender and ethnicity.</p