Estimating Mediated Effects with Survival Data
Estimating Mediated Effects with Survival Data
复制标题
用生存数据估计中介效应
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
D. Mackinnon
中科院分区：
文献类型：
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作者：
J. Tein;D. Mackinnon
中介分析有助于识别与预测变量和结果变量相关的因果序列中的变量。在许多研究中，结局是事件发生的时间，并应用生存分析。本研究使用两种生存分析方法：对数生存时间模型和对数风险时间模型来检验中介效应的点估计和区间估计。结果表明，在无删失数据条件下，系数积法（αs）和系数差法（τ − τ '）计算的中介效应完全相同的假设适用于对数生存时间生存分析，但不适用于对数风险时间生存分析。中介效应的标准误可以用δ公式、二阶泰勒级数公式和无偏公式计算。与普通最小二乘回归一致，三个公式产生类似的结果。尽管对数生存时间模型和对数风险时间模型使用不同的估计方法，但使用αs与seαs比值进行的显著性检验结果在两种方法之间具有可比性。然而，基于经验标准误差的显著性检验似乎比三种分析标准误差的显著性检验更保守。
Mediation analyses help identify variables in the causal sequence relating predictor variables to outcome variables. In many studies, outcomes are time until an event occurs and survival analyses are applied. This study examines the point and interval estimates of the mediated effect using two methods of survival analyses: the log-survival time and log-hazard time models. The results show that, under the condition of no censored data, the assumption that mediated effects calculated by the product of coefficients method (αs) and those calculated by the difference in coefficients method (τ − τ’) are identical does apply to log-survival time survival analyses but not to log-hazard time survival analyses. The standard error of the mediated effect can be calculated with the delta formula, the second order Taylor series formula, and the unbiased formula. Consistent with ordinary least squares regression, the three formulas yield similar results. Although the log-survival time model and the log-hazard time model utilize different estimation methods, the results of the significant tests, using the ratio of αs to seαs, were comparable between the two methods. However, the significance tests based on the empirical standard error appear to be more conservative than those from the three analytical standard errors.
影响因子：
3.8
作者：
MACKINNON, DP;WARSI, G;DWYER, JH
通讯作者：
DWYER, JH