Validation of Malay-vision disability assessment (VDA) questionnaire and its application to assess the functional disability among cataract patients of a tertiary medical centre in Malaysia

PURPOSE: This study aims to translate, culturally adapt, and validate the Malay-Visual Disability Assessment (VDA) questionnaire and to assess its applicability in evaluating functional disability among cataract patients of a tertiary medical centre in Malaysia.

METHODS: This cross-sectional, questionnaire-based study was divided into two phases. In Phase I, the pre-final version of Malay-VDA was validated by a panel of six experts, followed by cognitive debriefing with 10 respondents. Test-retest reliability was assessed using 35 participants. The reliability and validity of the Malay-VDA was tested using intraclass correlation coefficient (ICC) and content validity index (CVI). Phase II evaluated the visual function among 200 cataract patients using the validated Malay-VDA. Additionally, self-administered questionnaire was used to collect sociodemographic data of the respondents.

RESULTS: In Phase I, all items in Malay-VDA achieved an item-level CVI of > 0.8 for relevance and > 0.7 for clarity, with an overall CVI > 0.9. The test-retest reliability analysis demonstrated excellent reliability, with a single measures ICC of 0.998 (95% CI: 0.995-0.999, p