OBJECTIVES: While therapies for wet age-related macular degeneration (AMD) are well established, therapies in development for dry AMD would be without precedent. Economic evaluations of wet AMD therapies typically have relied on health states and utility values defined by visual acuity (VA), but the mechanisms of dry AMD can impair visual functioning without impairing VA. Our objective was to assess the suitability of VA-based utilities used in wet AMD for use in economic evaluations in dry AMD.
METHODS: This study reviewed four AMD utility studies and five wet AMD model structures and compared them with two guideline-based visual impairment definitions and the target populations for ongoing clinical trials in dry AMD. A crosswalk of VA ranges and associated utility values was developed to visualize alignment across studies. The AMD utility studies were assessed to determine whether they considered non-VA measures of visual functioning, included dry AMD patients, or controlled for dry AMD severity.
RESULTS: Lack of alignment in VA ranges was identified: none of the utility studies or model structures were aligned with guideline-based visual impairment definitions, and three of the five model structures used health state definitions that were not aligned with VA-based utility values. The utility studies were all conducted at least ten years ago, and only one utility study considered the interaction of VA and other visual functioning measures. While the utility studies all included dry AMD patients, the percentages of patients with dry AMD were low; moreover, dry AMD severity levels, when reported, were not aligned with dry AMD clinical trial populations.
CONCLUSIONS: Substantial limitations and inconsistencies were observed in utility values for wet AMD, and key data gaps were identified related to dry AMD. Studies designed specifically for dry AMD are needed to support economic evaluations of future dry AMD therapies.
