Development of the 25-item Cardiff Visual Ability Questionnaire for Children (CVAQC).
OBJECTIVE
To develop and validate a short questionnaire to assess self-reported visual ability in children and young people with a visual impairment.


METHODS
A list of 121 items was generated from 13 focus groups with children and young people with and without a visual impairment. A long 89-item questionnaire was piloted with 45 visually impaired children and young people using face-to-face interviews. Rasch analysis was used to analyse the response category function and to facilitate item removal ensuring a valid unidimensional scale. The validity and reliability of the short questionnaire were assessed on a group of 109 visually impaired children (58.7% boys; median age 13 years) using Rasch analysis and intraclass correlation coefficient (ICC).


RESULTS
The final 25-item questionnaire has good validity and reliability as demonstrated by a person separation index of 2.28 and reliability coefficient of 0.84. The items are well targeted to the subjects with a mean difference of -0.40 logit between item and person means, and an ICC of 0.89 demonstrates good temporal stability.


CONCLUSIONS
The Cardiff Visual Ability Questionnaire for Children (CVAQC) is a short, psychometrically robust and a self-reported instrument that works to form a unidimensional scale for the assessment of the visual ability in children and young people with a visual impairment.
Khadka
Jyoti
J
School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
Ryan
Barbara
B
Margrain
Tom H
TH
Court
Helen
H
Woodhouse
J Margaret
JM
D000203:Activities of Daily Living; D000293:Adolescent; D001294:Attitude to Health; D002648:Child; D002675:Child, Preschool; D004185:Disability Evaluation; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D011594:Psychometrics; D011795:Surveys and Questionnaires; D015354:Vision, Low / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000534:rehabilitation