Development of a Chinese version of the National Eye Institute Visual Function Questionnaire (CHI-VFQ-25) as a tool to study patients with eye diseases in Hong Kong

Background: To develop a Chinese version of the National Eye Institute Visual Function Questionnaire (CHI-VFQ-25) and to test its reliability and validity in a group of patients with eye diseases in Hong Kong. Methods: The National Eye Institute Visual Function Questionnaire (NEI-VFQ) was translated into Chinese. Patients were recruited from Hong Kong, and their demographic data and visual acuity were documented. Psychometric properties of the CHI-VFQ-25, including internal consistency, test-retest reliability, item-scale correlations and construct validity were tested. Results: 250 patients were recruited. The mean age of the patients was 66.04 (SD 14.00). 46% of them were male. The non-response rate and the floor and ceiling numbers of the CHI-VFQ-25 were calculated. The internal consistency was high in most subscales (except the general health and driving subscales), with Cronbach alpha ranging from 0.72-0.90. The test-retest reliability was excellent (intraclass correlation coefficient >0.90). Patients with worse visual acuity had significantly lower scores on the CHI-VFQ-25 supporting construct validity. Conclusion: The CHI-VFQ-25 is a reliable and valid tool for assessing the visual functions of Chinese patients with eye diseases in Hong Kong. Some questions had high non-response rates and should be substituted by the available alternatives.