Massof Robert W, Hsu Cynthia T, Baker Frank H, Barnett G David, Park William L, Deremeik James T, Rainey Carol, Epstein Cathy
Lions Vision Research and Rehabilitation Center, Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Arch Phys Med Rehabil. 2005 May;86(5):954-67. doi: 10.1016/j.apmr.2004.09.017.
To test the validity and reliability of measures of visual ability and to evaluate the relation between measurements made at the task level and measurements made at the goal level of a hierarchical model for visual disability.
Validation of a telephone-administered functional assessment instrument using Rasch analysis on self-assessment ratings.
Telephone interviews of respondents in their homes.
Consecutive series of 600 outpatients with low vision.
Not applicable.
Ordinal ratings of the difficulty in performing a subset of 337 tasks. Measures of the visual ability of each patient and the required visual ability to perform each task were made using the Andrich rating scale model. Measurement validity and reliability were tested statistically by comparing response patterns and distributions to measurement model expectations.
Results were consistent with a single visual ability construct. Patients' visual ability estimated from task difficulty ratings agreed with estimates from goal difficulty ratings ( r =.74); the difficulty of individual goals was equal to the weighted average of the difficulties of subsidiary tasks ( r =.79). However, conclusions from the Rasch analysis were not confirmed by principal components analysis of item residuals, which indicated that visual ability had a 2-dimensional structure, with 1 factor related to mobility and the other related to reading. Factor analysis on person measures estimated from subsets of functionally grouped items confirmed the 2-dimensional structure of visual ability.
Our study results confirm the hierarchical structure of the Activity Breakdown Structure model and show how the individualized Activity Inventory can produce measures of limitations in functional vision.
检验视觉能力测量方法的有效性和可靠性，并评估视觉障碍分层模型中任务层面测量与目标层面测量之间的关系。
使用Rasch分析对自我评估评分进行电话管理的功能评估工具的验证。
在受访者家中进行电话访谈。
连续600例低视力门诊患者。
不适用。
对337项任务子集执行难度的有序评分。使用安德里奇评分量表模型对每位患者的视觉能力以及执行每项任务所需的视觉能力进行测量。通过将反应模式和分布与测量模型预期进行比较，对测量的有效性和可靠性进行统计学检验。
结果与单一视觉能力结构一致。根据任务难度评分估计的患者视觉能力与根据目标难度评分的估计结果相符（r = 0.74）；各个目标的难度等于子任务难度的加权平均值（r = 0.79）。然而，项目残差的主成分分析并未证实Rasch分析的结论，该分析表明视觉能力具有二维结构，一个因素与活动能力相关，另一个因素与阅读相关。对功能分组项目子集估计的个体测量进行的因素分析证实了视觉能力的二维结构。
我们的研究结果证实了活动分解结构模型的层次结构，并展示了个性化活动量表如何能够得出功能性视力受限的测量结果。
