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. 2017 Aug 14;15(1):157.
doi: 10.1186/s12955-017-0726-5.

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

Jennifer Petrillo  1 , Neil M Bressler  2 , Ecosse Lamoureux  3   4 , Alberto Ferreira  5 , Stefan Cano  6
Affiliations

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

Jennifer Petrillo et al. Health Qual Life Outcomes. .

Abstract

Background: The NEI VFQ-25 has undergone psychometric evaluation in patients with varying ocular conditions and the general population. However, important limitations which may affect the interpretation of clinical trial results have been previously identified, such as concerns with reliability and validity. The purpose of this study was to evaluate the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and make recommendations for a revised scoring structure, with a view to improving its psychometric performance and interpretability.

Methods: Rasch Measurement Theory analyses were conducted in two stages using pooled baseline NEI VFQ-25 data for 2487 participants with retinal diseases enrolled in six clinical trials. In stage 1, we examined: scale-to-sample targeting; thresholds for item response options; item fit statistics; stability; local dependence; and reliability. In stage 2, a post-hoc revision of the scoring structure (VFQ-28R) was created and psychometrically re-evaluated.

Results: In stage 1, we found that the NEI VFQ-25 was mis-targeted to the sample, and had disordered response thresholds (15/25 items) and mis-fitting items (8/25 items). However, items appeared to be stable (differential item functioning for three items), have minimal item dependency (one pair of items) and good reliability (person-separation index, 0.93). In stage 2, the modified Rasch-scored NEI VFQ-28-R was assessed. It comprised two broad domains: Activity Limitation (19 items) and Socio-Emotional Functioning (nine items). The NEI VFQ-28-R demonstrated improved performance with fewer disordered response thresholds (no items), less item misfit (three items) and improved population targeting (reduced ceiling effect) compared with the NEI VFQ-25.

Conclusions: Compared with the original version, the proposed NEI VFQ-28-R, with Rasch-based scoring and a two-domain structure, appears to offer improved psychometric performance and interpretability of the vision-related quality of life scale for the population analysed.

Keywords: National Eye Institute Visual Functioning Questionnaire; Rasch Measurement Theory; Vision-related quality of life.

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Conflict of interest statement

Ethics approval and consent to participate

All data analysed here come from studies that were conducted in accordance with the Declaration of Helsinki and International Conference on Harmonization Good Clinical Practice guidelines. Approval for the studies was obtained from Ethics Committees or Institutional Review Boards at each contributing center. All patients provided written informed consent before participation in the studies.

Consent for publication

Not applicable.

Competing interests

SC is co-founder of Modus Outcomes, an outcomes research and consulting firm that provides services to pharmaceutical, medical device, and biotechnology companies. At the time of the study, JP and AF were employees of Novartis. AF currently holds stock from Novartis Pharma AG. EL has received consultancy fees from Novartis Pharma AG. NB declares that JHU School of Medicine has received research grants from Novartis.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Scale-To-Sample (Person–Item) Distribution for the NEI VFQ­-25. The top panel shows the distribution of pooled participants on the visual functioning scale. The bottom panel maps the NEI VFQ-25 items (grouped by subscale) onto the same visual functioning scale, highlighting item difficulty. Vertical dashed lines indicate the lower (left) and upper (right) extent of instrument coverage for the pooled participant population
Fig. 2
Fig. 2
Development of the NEI VFQ-­28­-R. Items retained from the unchanged NEI VFQ-25, and items from the NEI VFQ-25 Appendix, are indicated by solid arrows. NEI VFQ-25 items excluded from the NEI VFQ-28-R are indicated by terminated lines. NEI VFQ-25 items that had their response levels modified (response levels combined or one level rescored as missing data) are indicated by dashed arrows
Fig. 3
Fig. 3
Scale-To-Sample (Person–Item) Distribution for the NEI VFQ-­28­-R. The top panel shows the distribution of pooled participants on the visual functioning scale. The bottom panel maps the NEI VFQ-28-R items (grouped into two domains) onto the same visual functioning scale, highlighting item difficulty. Vertical dashed lines indicate the lower (left) and upper (right) extent of instrument coverage for the pooled participant population
See this image and copyright information in PMC

References

    1. Mangione CM, Berry S, Spritzer K, Janz NK, Klein R, Owsley C, Lee PP. Identifying the content area for the 51-item National Eye Institute Visual Function Questionnaire: results from focus groups with visually impaired persons. Arch Ophthalmol. 1998;116:227–233. - PubMed
    1. Mangione CM, Lee PP, Gutierrez PR, Spritzer K, Coleman AL. Development of the 25-item National Eye Institute visual function questionnaire. Arch Ophthalmol. 2001;119:1050–1058. doi: 10.1001/archopht.119.7.1050. - DOI - PubMed
    1. Bressler N, Chang T, Fine J, Dolan C, Ward J. Improved vision-related function after ranibizumab vs photodynamic therapy: a randomized clinical trial. Arch Ophthalmol. 2009;127:13–21. doi: 10.1001/archophthalmol.2008.562. - DOI - PubMed
    1. Chang T, Bressler N, Fine J, Dolan C, Ward J, Klesert T. Improved vision-related function after ranibizumab treatment of neovascular age-related macular degeneration: results of a randomized clinical trial. Arch Ophthalmol. 2007;125:1460–1469. doi: 10.1001/archopht.125.11.1460. - DOI - PubMed
    1. Mitchell P, Bandello F, Schmidt-Erfurth U, Lang G, Massin P, Schlingemann R, Sutter F, Simader C, Burian G, Gerstner O, et al. The RESTORE study: ranibizumab monotherapy or combined with laser versus laser monotherapy for diabetic macular edema. Ophthalmol. 2011;118:615–625. doi: 10.1016/j.ophtha.2011.01.031. - DOI - PubMed

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