Development of a new Rasch-based scoring algorithm for the National Eye Institute Visual Functioning Questionnaire to...

Area of Science:

• Ophthalmology
• Psychometrics
• Health Outcomes Research

Background:

• The National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) is widely used but has identified limitations in reliability and validity.
• Previous evaluations highlighted concerns that may impact the interpretation of clinical trial data for ocular conditions.

Purpose of the Study:

• To evaluate the psychometric performance of the NEI VFQ-25.
• To propose a revised scoring structure to enhance its psychometric properties and clinical interpretability.

Main Methods:

• Rasch Measurement Theory analyses were applied to pooled NEI VFQ-25 data from 2487 participants with retinal diseases.
• Two stages of analysis were performed: initial evaluation of the NEI VFQ-25 and subsequent psychometric re-evaluation of a revised scoring structure (VFQ-28R).

Main Results:

• The original NEI VFQ-25 exhibited issues with targeting, disordered response thresholds, and item misfit.
• The revised NEI VFQ-28-R, utilizing Rasch-based scoring and a two-domain structure (Activity Limitation and Socio-Emotional Functioning), demonstrated improved targeting, reduced item misfit, and eliminated disordered thresholds.
• The modified scale showed better performance compared to the original NEI VFQ-25.

Conclusions:

• The proposed NEI VFQ-28-R, with Rasch-based scoring and a two-domain structure, offers enhanced psychometric performance.
• This revised scale improves the interpretability of vision-related quality of life assessments for patients with retinal diseases.