Abstract
Purpose: :
Describe how two vision–specific functional status measures (VAQ and NEI–VFQ) are related to each other and to important clinical parameters.
Methods: :
CIGTS patients had clinic visits and quality of life telephone interviews every 6–months following treatment initiation. Clinical outcomes included visual field and visual acuity. The 33–item VAQ yields a mean total and eight subscale scores that range from 1 (Never) to 5 (Always). Higher scores indicate worse visual function. The 25–item NEI–VFQ yields a total score and 12 subscale scores that range from 0–100 with lower scores indicating worse visual function. Data from the first CIGTS visit after the NEI–VFQ became available are used for all outcomes. Descriptive statistics and Pearson correlation coefficients were generated.
Results: :
Completion rates for the 3 outcomes are: VAQ (n=510 of the original 607 subjects), NEI–VFQ (n=426), and clinical measures (n=480). Average mean deviation scores were –2.15 (better eye), –5.70 (worse eye), and –5.32 (study eye). The mean visual acuity score was 86.2 in the better eye and 80.5 in the worse eye. Subjects reported a mean VAQ total score of 1.9; mean subscale scores ranged from 2.3 (light–dark adaptation) to 1.5 (color discrimination). Subjects reported a mean NEI–VFQ total score of 91.6. Subscale means ranged from 68.3 (general health) to 98.1 (color vision). There were consistently significant correlations between VAQ and NEI–VFQ subscales ranging from –0.21 to –0.77. There were strong associations between the VAQ and NEI–VFQ total scores (–0.70) and two of the subscales shared in common: acuity/near vision (–0.68) and peripheral vision (–0.77). Correlations between the two functional status measures and clinical measures were in the appropriate direction but weaker. Worse eye visual acuity was weakly but significantly correlated with the VAQ total score (–0.20) and the NEI–VFQ total score (0.38).
Conclusions: :
Correlations between the VAQ and NEI–VFQ were highly significant, suggesting strong consistency among visual function measures. Patterns of association and the measures’ individual strengths will be discussed.
Keywords: quality of life • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: outcomes/complications