Programs for Assessment of Technology in Health (PATH) Research Institute, St Joseph's Healthcare Hamilton, 25 Main St. W., Suite 2000, Hamilton, ON, L8P 1H1, Canada,
Pharmacoeconomics. 2014 Feb;32(2):101-8. doi: 10.1007/s40273-013-0123-9.
Survival modeling techniques are increasingly being used as part of decision modeling for health economic evaluations. As many models are available, it is imperative for interested readers to know about the steps in selecting and using the most suitable ones. The objective of this paper is to propose a tutorial for the application of appropriate survival modeling techniques to estimate transition probabilities, for use in model-based economic evaluations, in the absence of individual patient data (IPD). An illustration of the use of the tutorial is provided based on the final progression-free survival (PFS) analysis of the BOLERO-2 trial in metastatic breast cancer (mBC).
An algorithm was adopted from Guyot and colleagues, and was then run in the statistical package R to reconstruct IPD, based on the final PFS analysis of the BOLERO-2 trial. It should be emphasized that the reconstructed IPD represent an approximation of the original data. Afterwards, we fitted parametric models to the reconstructed IPD in the statistical package Stata. Both statistical and graphical tests were conducted to verify the relative and absolute validity of the findings. Finally, the equations for transition probabilities were derived using the general equation for transition probabilities used in model-based economic evaluations, and the parameters were estimated from fitted distributions.
The results of the application of the tutorial suggest that the log-logistic model best fits the reconstructed data from the latest published Kaplan-Meier (KM) curves of the BOLERO-2 trial. Results from the regression analyses were confirmed graphically. An equation for transition probabilities was obtained for each arm of the BOLERO-2 trial.
In this paper, a tutorial was proposed and used to estimate the transition probabilities for model-based economic evaluation, based on the results of the final PFS analysis of the BOLERO-2 trial in mBC. The results of our study can serve as a basis for any model (Markov) that needs the parameterization of transition probabilities, and only has summary KM plots available.
生存模型技术越来越多地被用作健康经济评估决策模型的一部分。由于有许多模型可供选择，因此对于感兴趣的读者来说，了解选择和使用最合适模型的步骤至关重要。本文的目的是提出一个教程，用于在缺乏个体患者数据（IPD）的情况下，应用适当的生存模型技术来估计转移概率，以便用于基于模型的经济评估。本文提供了一个基于转移性乳腺癌（mBC）BOLERO-2 试验最终无进展生存（PFS）分析的使用教程的说明。
采用了 Guyot 及其同事的算法，然后在 R 统计软件包中运行，根据 BOLERO-2 试验的最终 PFS 分析，重建 IPD。应该强调的是，重建的 IPD 代表原始数据的近似值。然后，我们在 Stata 统计软件包中对重建的 IPD 拟合参数模型。进行了统计和图形检验，以验证发现的相对和绝对有效性。最后，使用基于模型的经济评估中使用的转移概率通用方程，从拟合分布中估计参数，得出转移概率方程。
应用教程的结果表明，对数逻辑模型最适合 BOLERO-2 试验最新发布的 Kaplan-Meier（KM）曲线重建数据。回归分析的结果在图形上得到了证实。为 BOLERO-2 试验的每个臂获得了一个转移概率方程。
本文提出并使用了一个教程，根据 mBC BOLERO-2 试验的最终 PFS 分析结果，估计基于模型的经济评估的转移概率。我们的研究结果可以作为任何需要转移概率参数化且只有摘要 KM 图可用的模型（马尔可夫）的基础。
