Brown H K, Kempton R A
Department of Public Health Sciences, University of Edinburgh, U.K.
Stat Med. 1994 Aug 30;13(16):1601-17. doi: 10.1002/sim.4780131602.
Residual maximum likelihood (REML) is a technique for estimating variance components in multi-classified data. In contrast to analysis of variance it can be routinely applied to unbalanced data and avoids some of the problems of biased variance estimates found with standard maximum likelihood estimation. The full REML method is of particular value for the analysis of unbalanced clinical trials as it allows recovery of all the available information on treatment effects which can lead to significant improvements in their precision. The use of REML has until recently been limited by heavy computational requirements and lack of readily available software. This is no longer such a restriction, however, as REML procedures are now available in several widely-used statistical packages, including BMDP, Genstat and SAS. This paper describes the REML technique and discusses its application to three common types of clinical trial: crossover, repeated measures and multicentre.
残差最大似然法（REML）是一种用于估计多分类数据中方差成分的技术。与方差分析不同，它可以常规应用于不平衡数据，并避免了标准最大似然估计中出现的一些方差估计偏差问题。完整的REML方法对于不平衡临床试验的分析具有特殊价值，因为它能够恢复所有关于治疗效果的可用信息，从而显著提高其精度。直到最近，REML的使用还受到计算要求高和缺乏易用软件的限制。然而，这不再是一个限制，因为现在在几个广泛使用的统计软件包中都有REML程序，包括BMDP、Genstat和SAS。本文描述了REML技术，并讨论了其在三种常见类型临床试验中的应用：交叉试验、重复测量试验和多中心试验。
