Assessment of a Chinese version of the 33-item Indian Vision Functioning Questionnaire revised for use in a Chinese cataract population

Objective There were three objectives in this study: (1)To develop a Chinese version of the 33-item Indian Vision Functioning Questionnaire. (2)To assess the applicability, item discrimination, reliability, and validity of the developed Chinese questionnaire in a Chinese cataract population. (3)To compare the vision-related quality of life (VRQoL) within different demographics of the study population. Methods In this cross-sectional investigation,language translation, back translation, and cross-cultural adaptation were used to revise the IND-VFQ-33 and create the Chinese Vision Functioning Questionnaire (IND-VFQ-CN-33). A total of 293 cataract in-patients waiting for surgery were interviewed by a single scorer, and 45 of them were independently interviewed again by another scorer. The IND-VFQ-CN-33 was tested for applicability, item discrimination, reliability, and validity based on internal consistency, inter-scorer reliability, content validity, and format validity. An independent samples t-test was used to compare the VRQoL of patients of different genders, ages, and educational levels. All patients were diveded into four vision groups according to their binocular distance visual acuity, a one-way analysis of variance was used to correlate quality of life with binocular distance visual acuity. Results The IND-VFQ-CN-33 demonstrated excellent applicability and item discrimination. There was good internal consistency (Cronbach's α=0.93) and excellent inter-scorer reliability. The scale-level content validity index value was 0.84. Eight common factors were extracted by exploratory factor analysis and explained 67.62% of the variance. Male patients scored higher on the psychosocial impact scale (t=-3.27, P<0.05), indicating reduced levels of psychosocial interactions. And illiterate patients scored higher on both the general functioning scale (t=-3.03, P<0.05) and the psychosocial impact scale (t=-3.45, P<0.05), indicating worse general functioning skills and psychosocial level. There were significant differences between the three scale scores among the four vision groups (F=3.66-24.37, P<0.05). Conclusion The IND-VFQ-CN-33 is suitable for evaluating VRQoL in Chinese cataract patients waiting for surgery. It shows good applicability, item discrimination, reliability, and validity. The psychosocial effects of cataracts are greater in male and illiterate patients. General functioning skills are more impaired in illiterate patients. VRQoL is influenced differently at different vision levels. Key words: Cataract; Quality of life; 33-item Indian Vision Functioning Questionnaire