The psychometric validity of the NEI VFQ-25 for use in a low-vision population

Abstract

PURPOSE. To determine the psychometric validity of the National Eye Institute-Visual Function Questionnaire (NEI VFQ- 25) and its subscale structure for use in people with low vision. METHODS. Two hundred thirty-two participants completed the NEI VFQ-25. Rasch analysis was used to test the psychometric performance of the questionnaire and each subscale. Factor models were hypothesized and tested with confirmatory factor analysis (CFA) and subsequently validated with Rasch analysis. RESULTS. For the overall scale, two rating scales had to be dichotomized and three mis fitting items removed to improve fit to the Rasch model. There was evidence of multidimensionality, indicating that the scale ..