Abstract
Purpose: :
To evaluate possible association between patients’ subjective evaluation of the significance of their glaucoma (using time trade-off utility values) and their actual ability to perform the activities of daily living (using a performance-based measure).
Methods: :
A cross-sectional study of one hundred and nineteen (n=119) consecutive patients with different types and stages of glaucoma from a tertiary ophthalmic center (Wills Eye Institute). Utility values were obtained by a trained interviewer, using the time trade-off method. Multivariate linear regression analyses were used to evaluate the relation of the utility value as a dependent variable and the independent variables (age, race, sex, visual acuity in the better eye, mean deviation in the better eye, number of glaucoma medications). Spearman’s linear correlation (rho) was used to relate time trade-off values to the scores of the various task-oriented subtests of ADREV, Pelli-Robson contrast sensitivity score (CS), integrated visual field (IVF) score, Esterman test score and National Eye Institute questionnaire (NEI-VFQ-25) score.
Results: :
The mean utility value for the group of 119 patients was 0.83 (SD 0.24; 95% CI, 0.78 to 0.87). The time trade-off values did not correlate with total ADREV score (r = 0.131, p=0.156) and with seven (from a total of nine) of its subtests. We found a weak correlation between utility values and two of the ADREV subtests: reading in reduced illumination and navigating through an obstacle course. Time trade-off values had no correlation with Pelli-Robson contrast sensitivity (r = 0.077, p=0.403), IVF (r = 0.103, p=0.265), Esterman Visual Field test (r = 0.104, p=0.260) and NEI-VFQ-25 (r = 0.134, p=0.146). 53 patients (55.5%) chose not to trade any years of life in return for perfect vision.
Conclusions: :
The majority of patients were unwilling to trade off years of life in return for perfect vision. In contrast to other reports, visual acuity in the better eye did not seem to affect utility values in our group of patients. Time trade-off scores did not correlate with IVF, contrast sensitivity, Esterman test, NEI-VFQ-25 and most of ADREV subtests.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment • visual acuity