Utility values and age-related macular degeneration

Abstract

Objective: To ascertain the utility values associated with age-related macular degeneration and varying degrees of visual loss. Design: A cross- sectional study. Participants: Eighty white patients with unilateral or bilateral age-related macular degeneration in 1 or both eyes, and visual loss to a minimum of the 20/40 level in at least 1 eye. Main Outcome Measures: Utility values were measured in 5 groups according to the visual acuity in the better-seeing eye, 1 (20/20 to 20/25), 2 (20/30 to 20/50), 3 (20/60 to 20/100), 4 (20/200 to 20/400), and 5 (counting fingers to light perception), using the time tradeoff and the standard gamble methods. Conventionally assigned anchor utility values were 1.0 for perfect health and 0.0 for death. Results: The mean utility value for the total group with age-related macular degeneration was 0.72 (95% confidence interval [CI], 0.66-0.78) using the time trade-off method and 0.81 (95% CI, 0.76-0.86) using the standard gamble method. Using the time trade-off method correlated with the visual acuity in the better-seeing eye, the results were as follow: group 1, 0.89 (95% CI, 0.825 0.96), group 2, 0.81 (95% CI, 0.73-0.89), group 3, 0.57 (95% CI, 0.47- 0.67), group 4, 0.52 (95% CI, 0.38-0.66), and group 5, 0.40 (95% CI, 0.29- 0.50). Thus, those patients in group I were willing to trade 11% of their remaining lifetime in return for perfect vision in each eye, whereas those in group 5 were willing to trade 60% of their remaining lifetime in return for perfect vision in each eye. Conclusion: Age-related macular degeneration causes a substantial decrease in patient utility values and is highly dependent on the degree of visual loss in the better-seeing eye.