Exploring the Research Decision Space: The Expected Value of Information for Sequential Research Designs
Exploring the Research Decision Space: The Expected Value of Information for Sequential Research Designs
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DOI：
10.1177/0272989x09344746
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发表时间：
2010-03-01
影响因子：
3.6
通讯作者：
Claxton, Karl
中科院分区：
文献类型：
--
作者：
Griffin, Susan;Welton, Nicky J.;Claxton, Karl
目的.研究部分完全信息期望值（EVPPI）及其对科研决策的影响。方法.预期信息价值分析评估了进一步研究的预期净收益。当完全信息的期望值（EVPI）超过额外研究的成本时，EVPPI可以用于识别对EVPI贡献最大的参数以及可以被忽略作为进一步研究的目标的没有EVPPI的参数。最近，人们注意到，一次性研究设计的低EVPPI参数可能与高EVPPI相关，当被视为序贯设计的一部分时。本文探讨了EVI分析中条件和序贯EVPPI的特点和作用。结果EVPPI的计算证明了单个参数，参数组，条件和顺序EVPPI。条件EVPPI是关于一个参数的完全信息的值，条件是已经获得关于另一个参数的完全信息。序贯EVPPI是序贯研究设计的完全信息值，首先研究一个参数，然后研究另一个参数。条件性EVPPI与单个EVPPI的单个参数不同。顺序EVPPI包括来自用于参数的联合EVPPI和用于顺序中的第一个参数的EVPPI的元素。序贯设计允许在第一个参数获得额外信息的基础上放弃对第二个参数的研究。结论. EVI分析所解决的研究决策空间可以通过将序贯EVPPI扩展到评估序贯研究设计。
Purpose. To investigate the expected value of partial perfect information (EVPPI) and the research decisions it can address. Methods. Expected value of information (EVI) analysis assesses the expected gain in net benefit from further research. Where the expected value of perfect information (EVPI) exceeds the costs of additional research, EVPPI can be used to identify parameters that contribute most to the EVPI and parameters with no EVPPI that may be disregarded as targets for further research. Recently, it was noted that parameters with low EVPPI for a one-off research design may be associated with high EVPPI when considered as part of a sequential design. This article examines the characteristics and role of conditional and sequential EVPPI in EVI analysis. Results. The calculation of EVPPI is demonstrated for single parameters, groups of parameters, and conditional and sequential EVPPI. Conditional EVPPI is the value of perfect information about one parameter, conditional on having obtained perfect information about another. Sequential EVPPI is the value of perfect information for a sequential research design to investigate first one parameter, then another. Conditional EVPPI differs from the individual EVPPI for a single parameter. Sequential EVPPI includes elements from the joint EVPPI for the parameters and the EVPPI for the first parameter in sequence. Sequential designs allow abandonment of research on the second parameter on the basis of additional information obtained on the first. Conclusions. The research decision space addressed by EVI analyses can be widened by incorporating sequential EVPPI to assess sequential research designs.