Department of Public Health, Erasmus University Medical Centre, Rotterdam, The Netherlands.
Value Health. 2011 Jun;14(4):438-42. doi: 10.1016/j.jval.2010.09.009. Epub 2011 May 19.
To call attention to the influence of the number of birth-cohorts used in cost-effectiveness analysis (CEA) models on incremental cost-effectiveness ratios (ICERs) under differential discounting.
The consequences of increasing the number of birth-cohorts are demonstrated using a CEA of cervical cancer prevention as an example. The cost-effectiveness of vaccinating 12-year-old girls against the human papillomavirus is estimated with the MISCAN microsimulation screening analysis model for 1, 10, 20, and 30 birth-cohorts. Costs and health effects are discounted with equal rates of 4% and alternatively with differential rates of 4% and 1.5% respectively. The effects of increasing the number of cohorts are shown by comparing the ICERs under equal and differential discounting.
The ICER decreases as the number of cohorts increases under differential discounting, but not under equal discounting.
The variation of ICERs with the number of cohorts under differential discounting prompts questions regarding the appropriate specification of CEA models and interpretation of their results. In particular, it raises concerns that arbitrary variation in study specification leads to arbitrary variation in results. Such variations could lead to erroneous policy decisions. These findings are relevant to CEA guidance authorities, CEA practitioners, and decision makers. Our results do not imply a problem with differential discounting per se, yet they highlight the need for practical guidance for its use.
提醒人们注意在差异化贴现下，成本效益分析（CEA）模型中使用的出生队列数量对增量成本效益比（ICER）的影响。
以宫颈癌预防的 CEA 为例，展示了增加出生队列数量的后果。使用 MISCAN 微观模拟筛查分析模型，针对 1、10、20 和 30 个出生队列，估计了对 12 岁女孩接种人乳头瘤病毒疫苗的成本效益。成本和健康效果以相等的 4%贴现率或分别以 4%和 1.5%的差异化贴现率贴现。通过比较差异化贴现和均等贴现下的 ICER 来显示增加队列数量的效果。
在差异化贴现下，随着队列数量的增加，ICER 会降低，但在均等贴现下则不会。
差异化贴现下 ICER 随队列数量的变化引发了对 CEA 模型适当规范和结果解释的问题。特别是，它引起了人们对研究规范的任意变化会导致结果的任意变化的担忧。这种变化可能导致错误的政策决策。这些发现与 CEA 指导机构、CEA 从业者和决策者有关。我们的结果并不意味着差异化贴现本身存在问题，但它们强调了需要对其使用提供实际指导。
