Peking University Third Hospital, Beijing, China.
Beijing Fengtai Hospital, Beijing, China.
Acta Ophthalmol. 2021 Jun;99(4):e480-e488. doi: 10.1111/aos.14606. Epub 2020 Sep 17.
The present study aimed to investigate and compare the psychometric properties of the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) and the Visual Function Index-14 (VF-14) in a large sample of patients with cataracts.
A total of 1052 patients with bilateral age-related cataracts were recruited in the study. Patients with other comorbidities that severely impacted vision were excluded. Participants completed the two questionnaires in random order. Classical test theory and Rasch analyses were used to assess the psychometric properties of the questionnaires.
Complete data were obtained from 899 patients. The mean overall index score on the NEI VFQ-25 was 76.1 ± 19.0, while that on the VF-14 was 46.5 ± 15.0. Cronbach's α-values for the NEI VFQ-25 and VF-14 were 0.89 and 0.95, respectively. Ceiling effects were observed on nine of the 12 subscales in the NEI VFQ-25. The correlation between total scores on the NEI VFQ-25 and VF-14 was moderate (r = 0.600; p < 0.001), and subscales of the NEI VFQ-25 were weakly or moderately correlated with the similar domains on the VF-14. Rasch analysis revealed ordered category thresholds and sufficient person separation for both instruments, while the two questionnaires had critical deficiencies in unidimensionality, targeting and differential item functioning.
Neither the NEI VFQ-25 nor VF-14 is optimal for the assessment of vision-related quality of life in typical Chinese patients with cataracts. The potential deficiencies of the questionnaires should be taken into consideration prior to application of the instruments or interpretation of the results.
本研究旨在调查和比较国家眼科研究所视觉功能问卷-25 版（NEI VFQ-25）和视觉功能指数-14 版（VF-14）在大量白内障患者中的心理测量特性。
研究共招募了 1052 名双侧年龄相关性白内障患者。排除了其他严重影响视力的合并症患者。患者以随机顺序完成这两个问卷。采用经典测试理论和 Rasch 分析评估问卷的心理测量特性。
从 899 名患者中获得了完整的数据。NEI VFQ-25 的总体指数平均得分为 76.1±19.0，而 VF-14 的平均得分为 46.5±15.0。NEI VFQ-25 和 VF-14 的 Cronbach's α 值分别为 0.89 和 0.95。在 NEI VFQ-25 的 12 个分量表中，有 9 个存在天花板效应。NEI VFQ-25 总分与 VF-14 之间的相关性适中（r=0.600；p<0.001），并且 NEI VFQ-25 的分量表与 VF-14 的相似领域呈弱相关或中度相关。Rasch 分析显示，两种工具均具有有序类别阈值和足够的个体分离，但这两种问卷在一维性、目标和差异项目功能方面存在严重缺陷。
NEI VFQ-25 和 VF-14 均不适用于评估中国典型白内障患者的视觉相关生活质量。在应用这些工具或解释结果之前，应考虑问卷的潜在缺陷。
