The Anticipatory Effects of Medicare Part D on Drug Utilization

描述(由申请人提供)：2003年，《医疗保险处方药、改进和现代化法案》(MMA)签署成为法律，扩大了医疗保险计划，将处方药的自愿保险覆盖范围包括在内。这项计划被称为D部分，于2006年1月1日开始实施。鉴于该计划的主要目标之一是扩大获得处方药的机会，评估对药物利用的影响是首要的。然而，由于D部分是在2003年12月MMA通过时宣布的，这一事实使确定这种影响变得复杂，也就是该计划实施的两年前。具有前瞻性的个人可能已经预见到补贴保险带来的未来价格变化，并在D部分生效之前改变了他们的药品支出。该项目将估计对2003年宣布的D部分的因果需求反应。这个项目有三个方面的影响。首先，这项调查量化了在政策实施前宣布政策的影响，以及对计划评估的后果。政策宣布可以对重要成果产生实际影响(与其实施效果分开)的想法在项目评估文献中基本上没有被探索过。其次，该项目首次在毒品需求的背景下对前瞻性行为进行了测试。在许多其他情况下，优化个人根据每个时期的相对价格来权衡当前和未来的消费。然而，目前尚不清楚个人在决定当前的药品消费水平时是否对未来价格的预期做出了反应。第三，该项目在先前对D部分使用效果的估计中发现了一个潜在的巨大偏差来源。在存在预期反应的情况下，这些研究--根据政策实施前一两年的使用变化确定计划效果--将错误地陈述D部分的净影响。经验方法通过比较D部分宣布前后慢性药物相对于急性药物的使用情况来确定是否存在因果预期反应。这一战略取决于这样一个观察，即急性药物治疗的疾病基本上是不可预测的，因此它们的需求可能只对当前价格做出反应。而慢性药物使用可能会对预期的未来降价做出负面或积极的反应。该项目还使用其他群体(如老年人和近老年人)对这一声明的暴露程度的变化来确定影响。最后，该项目产生了D部分的第一个治疗效果利用估计，该估计考虑了计划前的预期反应。 公共卫生相关性：本项目旨在评估D部分对药物使用的因果预期影响。评估D部分的使用效果对于评估政策的主要目标--扩大获得处方药的机会--是否实现以及评估该计划未来的财务偿付能力是很重要的。考虑到预期反应和实施时反应的综合影响，将比以前仅考虑实施效果的研究更准确地估计方案效果。

DESCRIPTION (provided by applicant): In 2003, the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) was signed into law, which expanded the Medicare program to include voluntary insurance coverage for prescription drugs. This program, known as Part D, was implemented on January 1, 2006. Given that one of the program's primary aims was to expand access to prescription drugs, evaluating the impact on drug utilization is of first-order importance. However, identifying this effect is complicated by the fact that Part D was announced with the passage of the MMA in December 2003, two years before the program was implemented. Forward looking individuals may have anticipated future price changes brought about by subsidized coverage and changed their drug spending before Part D took effect. This project will estimate the causal demand response to the announcement of Part D in 2003. There are three implications of this project. First, this investigation quantifies the effect of announcing a policy before its implementation, with consequences for program evaluation. The idea that policy announcements can have real effects (separate from their implementation effect) on important outcomes has been largely unexplored in the program evaluation literature. Second, the project provides the first test of forward-looking behavior in the context of drug demand. In many other contexts, optimizing individuals trade-off present and future consumption based on the relative prices in each period. However, it is not known whether individuals are responsive to expectations of future prices when determining current drug consumption levels. Third, the project identifies a potentially large source of bias in the previous estimates of the utilization effect of Part D. To the extent that there was an anticipatory response, these studies- which identify the program effect from changes in utilization relative to the year or two just prior to the policy's implementation-- will misstate the net effect of Part D. The empirical approach identifies whether there is a causal anticipatory response by comparing utilization for chronic drugs relative to acute drugs before and after the announcement of Part D. This strategy hinges on the observation that acute drugs treat illnesses that are largely unpredictable, thus their demand is likely to respond only to current prices, whereas chronic drug use may respond negatively or positively to anticipated future price reductions. This project also uses variation in exposure to the announcement across other groups such as the elderly and near-elderly to identify the effect. Finally, this project produces the first treatment effect utilization estimates of Part D that take into account a pre-program anticipatory response. PUBLIC HEALTH RELEVANCE: This project seeks to estimate the causal anticipatory effects of Part D on drug utilization. Estimating the utilization effect of Part D is important for evaluating whether the primary aims of the policy-- expanding access to prescription drugs-- were achieved and for assessing the program's future financial solvency. Accounting for the combined effect of the anticipatory response and the response at implementation will produce a more accurate estimate of the program effect than previous studies that have considered the implementation effect alone.