模型评价方法的比较:正态化预测分布误差与可视化预测检验
Comparison study of model evaluation methods: normalized prediction distribution errors vs visual predictive check
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摘要:
本研究旨在比较不同实验设计下正态化预测分布误差 (normalised prediction distribution errors, NPDE) 和可视化预测检验 (visual predictive check, VPC) 对模型的评价效能。本研究通过仿真方法, 分别在采血时间相同的单剂量、多剂量给药以及采血时间不同的多剂量给药3种条件下, 比较考察NPDE和VPC对正确模型、参数群体典型值偏差或参数个体间变异 (inter-individual variability) 偏差造成的错误模型的评价能力。结果显示, VPC没有明确的判断标准并且会受到实验设计的影响, 采血时间不同的多剂量给药实验设计下, VPC结果已很难辨别并且对模型的辨识能力也明显下降; 而NPDE具有相应的统计学检验, 其模型评价能力不受实验设计因素的影响。结果提示, 临床研究中VPC不适用的数据及模型, NPDE依然可以进行合理的评价。
Abstract:The objective of this study is to compare the normalized prediction distribution errors (NPDE) and the visual predictive check (VPC) on model evaluation under different study designs. In this study, simulation method was utilized to investigate the capability of NPDE and VPC to evaluate the models. Data from the false models were generated by biased parameter typical value or inaccurate parameter inter-individual variability after single or multiple doses with the same sampling time or multiple doses with varied sampling time, respectively. The results showed that there was no clear statistic test for VPC and it was difficult to make sense of VPC under the multiple doses with varied sampling time. However, there were corresponding statistic tests for NPDE and the factor of study design did not affect NPDE significantly. It suggested that the clinical data and model which VPC was not fit for could be evaluated by NPDE.
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