Stangl D K, Greenhouse J B
Institute of Statistics and Decision Sciences, Duke University, USA.
Lifetime Data Anal. 1998;4(1):5-28. doi: 10.1023/a:1009644308160.
The National Institute of Mental Health (NIMH) Collaborative Study of Long-Term Maintenance Drug Therapy in Recurrent Affective Illness was a multicenter randomized controlled clinical trial designed to determine the efficacy of a pharmacotherapy for the prevention of the recurrence of unipolar affective disorders. The outcome of interest in this study was the time until the recurrence of a depressive episode. The data show much heterogeneity between centers for the placebo group. The aim of this paper is to use Bayesian hierarchical survival models to investigate the heterogeneity of placebo effects among centers in the NIMH study. This heterogeneity is explored in terms of the marginal posterior distributions of parameters of interest and predictive distributions of future observations. The Gibbs sampling algorithm is used to approximate posterior and predictive distributions. Sensitivity of results to the assumption of a constant hazard survival distribution at the first stage of the hierarchy is examined by comparing results derived from a two component exponential mixture and a two component exponential changepoint model to the results derived from an exponential model. The second component of the mixture and changepoint models is assumed to be a surviving fraction. For each of these first stage parametric models sensitivity of results to second stage prior distributions is also examined.
美国国立精神卫生研究所（NIMH）开展的复发性情感障碍长期维持药物治疗协作研究是一项多中心随机对照临床试验，旨在确定药物疗法预防单相情感障碍复发的疗效。本研究关注的结果是直至抑郁发作复发的时间。数据显示，安慰剂组各中心之间存在很大异质性。本文的目的是使用贝叶斯分层生存模型来研究NIMH研究中各中心安慰剂效应的异质性。这种异质性是根据感兴趣参数的边际后验分布和未来观察的预测分布来探索的。吉布斯采样算法用于近似后验分布和预测分布。通过将来自双组分指数混合模型和双组分指数变点模型的结果与来自指数模型的结果进行比较，检验了结果对分层第一阶段恒定风险生存分布假设的敏感性。混合模型和变点模型的第二个组分被假定为一个生存分数。对于这些第一阶段参数模型中的每一个，还检验了结果对第二阶段先验分布的敏感性。
