Karnon Jonathan, Czoski-Murray Carolyn, Smith Kevin J, Brand Christopher
School of Population Health and Clinical Practice, University of Adelaide, Adelaide, Australia.
Med Decis Making. 2009 May-Jun;29(3):304-16. doi: 10.1177/0272989X08327491. Epub 2009 Jan 6.
Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness. It is likely that treatment of AMD at earlier stages is more effective than later treatment; thus, screening for AMD should be considered. The aim of this study was to develop a natural history model of AMD to estimate the cost-effectiveness of screening.
A hybrid cohort/individual sampling decision analytic model was developed. Primary data sets, expert elicitation, and data from the literature were used to populate the model. To incorporate joint parameter uncertainty, and to populate unobservable parameters, an innovative form of probabilistic calibration was applied to a range of output parameters.
In the reference case, annual screening from age 60 y is the most cost-effective option, although this is subject to high levels of uncertainty. Alternative, age-specific utility values show that screening is predicted to be less cost-effective, assuming interventions that reduce progression to wet AMD moderately improve the cost-effectiveness of screening, whereas the addition of anti-vascular endothelial growth factor therapy for juxtafoveal or subfoveal wet AMD lesions improves the cost-effectiveness of screening significantly.
The extent of the uncertainty around the mean results, and the additional resources and possible reorganization of services required to implement screening, indicate that it may be preferable to reduce the level of uncertainty before implementing screening for AMD. Initial actions may be best targeted at assessing how routine data may be used to describe clinical presentation, a screening pilot study, and a secondary costing study.
年龄相关性黄斑变性（AMD）是视力损害和失明的主要原因。早期治疗AMD可能比晚期治疗更有效；因此，应考虑对AMD进行筛查。本研究的目的是建立一个AMD自然史模型，以评估筛查的成本效益。
建立了一个混合队列/个体抽样决策分析模型。主要数据集、专家意见和文献数据用于填充模型。为了纳入联合参数不确定性并填充不可观测参数，一种创新形式的概率校准被应用于一系列输出参数。
在参考案例中，从60岁开始每年进行筛查是最具成本效益的选择，尽管这存在高度不确定性。另外，特定年龄的效用值表明，假设减少进展为湿性AMD的干预措施适度提高了筛查的成本效益，而对黄斑旁或黄斑下湿性AMD病变添加抗血管内皮生长因子治疗则显著提高了筛查的成本效益，预计筛查的成本效益较低。
平均结果周围不确定性的程度，以及实施筛查所需的额外资源和可能的服务重组表明，在对AMD实施筛查之前，最好先降低不确定性水平。初步行动可能最好针对评估如何使用常规数据来描述临床表现、开展一项筛查试点研究以及一项二次成本核算研究。
