Development of the 25-item Cardiff Visual Ability Questionnaire for Children (CVAQC)

Jyoti Khadka (1) , Barbara Ryan (1) , Tom Margrain (1) , Helen Court (1) , J Margaret Woodhouse (1)

1 Cardiff University

Aims: 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 analyze 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 ICC of 0.89 demonstrate a good temporal stability. Conclusion: The CVAQC is a short, psychometrically robust, self reported instrument which works to form a unidimensional scale for the assessment of the visual ability in children and young people with a visual impairment

Mots clés: Low vision aid; Child health (paediatrics)

Jyoti Khadka, Barbara Ryan, Tom Margrain, Helen Court, J Margaret Woodhouse. Development of the 25-item Cardiff Visual Ability Questionnaire for Children (CVAQC). British Journal of Ophthalmology, 2010, 94 (6), pp.730. ⟨10.1136/bjo.2009.171181⟩. ⟨hal-00557344⟩