Instrumental Variable Methods for Censored Cost Data and an Application in Prosta

描述（由申请人提供）：有许多研究的分析任务是估计具有特定病症或慢性疾病的治疗组在规定时间内的总成本。这些包括疾病成本研究，如疾病的增量或总终身成本，成本效益的组成部分，以及其他形式的医疗保健经济评估。然而，回答这些问题需要解决一系列统计和计量经济学问题，包括个体患者观察的可变时间段，疾病或治疗过程中的波动成本，患者死亡时的成本上升以及在感兴趣的终点（例如治愈，死亡）之前对数据进行行政审查。这些分析障碍因扭曲的费用数据和根据预期的治疗特异性效益、费用和风险自行选择治疗而导致的治疗决定的内隐性而变得更加复杂。 我们的建议将制定创新方法，以综合方式解决其中每一个问题。拟议的工作将推进卫生研究中成本分析和经济评价领域的四个广泛领域。首先，它将提供并验证一种一致的方法来估计成本，这种方法的特点是随着时间的推移而变化的支出率，正确的审查，以及通常在死亡前观察到的支出升级。第二，它将桥接两个大型文献的方法，一个是建模偏斜的成本数据（右删失），另一个是在治疗异质性的存在下使用IV。第三，它可以突出未观察到的患者偏好和疾病严重程度可能在前列腺癌背景下产生治疗效果异质性中的作用。最后，这项工作有很大的可能性，产生新的信息比较成本估计在前列腺癌，可以作为重要的投入到成本效益和其他政策分析。

DESCRIPTION (provided by applicant): There are many studies where the analytical task is to estimate the total costs over a defined period of time for a treatment group with a particular condition or chronic disease. These include cost of illness studies such as incremental or total lifetime costs for a disease, the components of cost effectiveness, and other forms of economic evaluation in health care. However, answering such questions requires addressing a range of statistical and econometric issues that include variable time periods of observation for individual patients, fluctuating costs over the course of the disease or treatment, the escalation of costs when the patient is dying and administrative censoring of data prior to the endpoint of interest (e.g. cure, death). These analytical obstacles are compounded by skewed cost data and the endogeneity of treatment decisions caused by self-selection into treatment based on expected idiosyncratic benefits, costs and risks of treatments. Our proposal will develop innovative methods to address each of these problems in a consolidated manner. The proposed work will advance four broad areas in the fields of cost analysis and economic evaluation in health studies. First, it will provide and validate a consistent method of estimating costs in a setting characterized by varying rates of spending over time, right censoring, and the escalation of expenditures commonly observed just before death. Second, it will bridge two large literatures on methods, one on modeling skewed cost data (with right censoring) and the other on the use of IV in the presence of treatment heterogeneity. Third, it can highlight the role that unobserved patient preferences and disease severity may have in generating treatment effect heterogeneity in the context of prostate cancer. Lastly, this work has a high likelihood of generating new information about the comparative cost estimates in prostate cancer which can serve as important inputs into cost-effectiveness and other policy analyses.