Walter S D, Feinstein A R, Wells C K
Am J Epidemiol. 1987 Feb;125(2):319-23. doi: 10.1093/oxfordjournals.aje.a114532.
The authors present a coding scheme for ordinal independent variables which may be used in various forms of regression analysis. The scheme is useful in dose-response analyses, when the objective is to identify contrasts in the dependent (or response) variable between successive levels of the independent variable, or to identify critical threshold values of the independent variables at which significant changes occur in the response. An example is given of evaluating the survival of lung cancer patients according to their stage of symptomatology. The authors discuss the interpretation of the regression coefficients when this coding scheme is used with linear regression, logistic regression, or in the proportional hazards regression model.
作者提出了一种用于有序自变量的编码方案，该方案可用于各种形式的回归分析。当目标是识别自变量连续水平之间因变量（或响应变量）的差异，或识别自变量的临界阈值（在该阈值下响应发生显著变化）时，该方案在剂量反应分析中很有用。给出了一个根据肺癌患者症状阶段评估其生存率的示例。作者讨论了在将此编码方案用于线性回归、逻辑回归或比例风险回归模型时回归系数的解释。
