Optimizing the ULV-VFQ for Clinical Use Through Item Set Reduction: Psychometric Properties and Trade-Offs.

ABSTRACT:

Purpose

We examine the dimensionality of the 150-item visual functioning questionnaire for individuals with ultralow vision (ULV-VFQ) and develop representative abbreviated versions, facilitating clinical use, while retaining compatibility with a 17-item performance assessment.

Methods

Subsets with 50 and 23 items covering the full difficulty range were selected, with evenly spaced item measures (IMs) and good representation of visual aspects and functional domains. Person measures (PMs) for the anchored subsets were derived through Rasch analysis of data from 80 respondents.

Results

Fit statistics for the reduced item sets were similar to those for the full set, with reliabilities at or above 95%. Mean PMs in the reduced sets were within 0.8 standard errors (SEs) of

SUBMITTER: Dagnelie G 

PROVIDER: S-EPMC5450924 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature