Abstract
Purpose :
To assess the validity of two new composite scales for the NEI-VFQ-25 for vision-related tasks and well-being and estimate the impact of a change of visual acuity (VA) of 2 lines on quality of life (QOL).
Methods :
A population-based sample of 3800 Latino adults residing in La Puenta, CA, age 40 years and older at baseline, underwent complete ophthalmologic exams including measurements of presenting and best-corrected distance VA using the Early Treatment Diabetic Retinopathy Study protocol. Visual-related QOL was assessed using the NEI-VFQ-25, and change in QOL assessed with the reliable change index (RCI). The 2 new composite scores were developed out of task and well-being-related questions using confirmatory factor analysis (CFA). Examinations were completed at baseline (2000-2003), 4 years (2004-2008), and 8 years of follow-up (2009-2013). Change in QOL and VA were assessed between baseline and 8-year follow-up using covariate-adjusted multinomial models.
Results :
Compared to the overall composite score for the NEI-VFQ-25, introducing separate composites for task and well-being statistically significantly improved the CFA model (p<.001). The mean overall composite score at baseline was 85.0 (SD 13.0), while the task and well-being composites were 87.8 (SD 14.1) and 76.0 (SD 13.4), respectively. For the overall, task, and well-being composites, a 2-line or greater improvement in VA was associated with a covariate-adjusted odds ratio (OR) of 1.91 (95% CI 1.30, 2.82), 1.58 (95% CI 1.04, 2.41), and 1.93 (95% CI 1.19, 3.15), respectively, for a meaningful improvement (RCI > 1.96) in QOL. For the overall, task, and well-being composites, a 2-line loss in VA had an OR of 1.51 (95% CI 1.06, 2.14), 1.56 (95% CI 1.05, 2.33), and 1.23 (95% CI 0.82, 1.86), respectively, for meaningful reduction (RCI < -1.96) in QOL.
Conclusions :
Interpretability of the NEI-VFQ-25 with respect to improvement in VA may be gained by use of 2 separate composite scores focused on vision-related daily tasks and well-being. Use of the 2 scales improved the fit to the data over a single composite. The mean well-being score was lower than that of the task and overall scores. 2-line loss in VA led to a reduction in QOL for all scales, but this was less pronounced for well-being. A 2-line increase in VA led to an improvement in QOL for all scales, but this effect was less pronounced for task-related QOL.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.