Tu Yu-Kang, Baelum Vibeke, Gilthorpe Mark S
Leeds Dental Institute, University of Leeds, Leeds, UK.
Eur J Oral Sci. 2005 Aug;113(4):271-8. doi: 10.1111/j.1600-0722.2005.00228.x.
The relationship between initial disease status and subsequent change following treatment has attracted great interest in dental research. However, medical statisticians have repeatedly warned against correlating/regressing change with baseline because of two methodological concerns known as mathematical coupling and regression to the mean. In general, mathematical coupling occurs when one variable directly or indirectly contains the whole or part of another, and the two variables are then analyzed by using correlation or regression. Consequently, the statistical procedure of testing the null hypothesis - that the coefficient of correlation or the slope of regression is zero - may become inappropriate. Regression to the mean occurs with any variable that fluctuates within an individual or a population, either owing to measurement error and/or to physiological variation. The aim of this article was to clarify the conceptual confusion around mathematical coupling and regression to the mean within the statistical literature, and to correct a popular misconception about the correct analysis of the relationship between change and initial value. As examples that use inappropriate methods to analyze the relationship between change and baseline are still found in leading dental journals, this article seeks to help oral health researchers understand these problems and explain how to overcome them.
初始疾病状态与治疗后后续变化之间的关系在牙科研究中引起了极大关注。然而，医学统计学家一再警告不要将变化与基线进行关联/回归分析，原因在于存在被称为数学耦合和均值回归的两个方法学问题。一般来说，当一个变量直接或间接包含另一个变量的全部或部分时，就会出现数学耦合，然后使用相关性或回归分析这两个变量。因此，检验零假设（即相关系数或回归斜率为零）的统计程序可能会变得不恰当。均值回归发生在个体或群体中任何因测量误差和/或生理变异而波动的变量上。本文的目的是澄清统计文献中围绕数学耦合和均值回归的概念混淆，并纠正关于变化与初始值之间关系正确分析的一个普遍误解。由于在领先的牙科期刊中仍能发现使用不恰当方法分析变化与基线之间关系的例子，本文旨在帮助口腔健康研究人员理解这些问题，并解释如何克服它们。
