Gothwal Vijaya K, Sumalini Rebecca, Bharani Seelam, Reddy Shailaja P, Bagga Deepak K
Meera and L. B. Deshpande Centre for Sight Enhancement, Vision Rehabilitation Centres, L. V. Prasad Eye Institute, Hyderabad, India.
Optom Vis Sci. 2012 Nov;89(11):1601-10. doi: 10.1097/OPX.0b013e31826ca291.
The L. V. Prasad-Functional Vision Questionnaire (LVP-FVQ) was developed using Rasch analysis to assess self-reported difficulties in performing daily tasks in school children with visual impairment (VI) in India. However, the LVP-FVQ has psychometric problems of inadequate measurement precision and lack of detailed assessment of dimensionality. Furthermore, items pertaining to use of technology are lacking. The aim of this study was to present the development and validation of the second version of LVP-FVQ (LVP-FVQ II).
Development of LVP-FVQ II involved extracting items from other similar questionnaires (albeit developed for Western populations) and focus group discussions of children with VI and their parents that resulted in a 32-item pilot questionnaire. Overall, six items from the LVP-FVQ were retained. The questionnaire underwent pilot testing in 25 such children, following which a 27-item LVP-FVQ II emerged, and this was administered to 150 children with VI. Response to each item was rated on a three-category scale. Rasch analysis was used to validate the LVP-FVQ II.
Rating scale was used by participants as was intended to. Four mobility-related items required deletion, as these did not contribute toward measurement of a single construct, indicating a secondary dimension. Deletion of the four items resulted in the 23-item unidimensional LVP-FVQ II, with good measurement precision, effective targeting of item difficulty to participant ability, and lack of notable differential item functioning. The LVP-FVQ II has high reliability, indicating that it is effectively able to discriminate between visual disability of school children in India, and is valid across age, gender, duration of VI, and location of residence.
Given the superior measurement properties and the interval-level scores, the LVP-FVQ II appears to offer advantages over LVP-FVQ in assessment of difficulties in performing daily tasks in this population. It can be adapted for use in other developing countries.
L.V.普拉萨德功能性视力问卷（LVP - FVQ）通过拉施分析开发，用于评估印度视力受损（VI）学童在执行日常任务时自我报告的困难。然而，LVP - FVQ存在测量精度不足和维度缺乏详细评估的心理测量问题。此外，缺乏与技术使用相关的项目。本研究的目的是介绍LVP - FVQ第二版（LVP - FVQ II）的开发与验证。
LVP - FVQ II的开发包括从其他类似问卷（尽管是为西方人群开发）中提取项目，以及对视力受损儿童及其父母进行焦点小组讨论，从而形成一份32项的预测试问卷。总体而言，保留了LVP - FVQ中的6个项目。该问卷在25名此类儿童中进行了预测试，之后形成了一份27项的LVP - FVQ II，并将其施用于150名视力受损儿童。对每个项目的回答按三类量表进行评分。使用拉施分析来验证LVP - FVQ II。
参与者按预期使用了评分量表。四个与移动性相关的项目需要删除，因为它们对单一结构的测量没有贡献，表明存在一个次要维度。删除这四个项目后得到了23项的单维LVP - FVQ II，具有良好的测量精度，项目难度能有效针对参与者能力，且不存在明显的项目功能差异。LVP - FVQ II具有高可靠性，表明它能够有效区分印度学童的视力残疾情况，并且在年龄、性别、视力受损持续时间和居住地点方面都是有效的。
鉴于其优越的测量特性和区间水平分数，LVP - FVQ II在评估该人群执行日常任务的困难方面似乎比LVP - FVQ更具优势。它可以改编用于其他发展中国家。
