Department of Mathematics, Washington and Lee University, 204 W Washington St, Lexington, VA 24450, USA.
Department of Public Health Sciences, Medical University of South Carolina.
Int J Biostat. 2022 May 10;18(2):613-625. doi: 10.1515/ijb-2021-0071. eCollection 2022 Nov 1.
Dichotomization is often used on clinical and diagnostic settings to simplify interpretation. For example, a person with systolic and diastolic blood pressure above 140 over 90 may be prescribed medication. Blood pressure as well as other factors such as age and cholesterol and their interactions may lead to increased risk of certain diseases. When using a dichotomized variable to determine a diagnosis, if the interactions with other variables are not considered, then an incorrect threshold for the continuous variable may be selected. In this paper, we compare single dichotomization with joint dichotomization; the process of simultaneously optimizing cutpoints for multiple variables. A simulation study shows that simultaneous dichotomization of continuous variables is more accurate in recovering both 'true' thresholds given they exist.
二分法常用于临床和诊断环境中，以简化解释。例如，收缩压和舒张压均高于 140/90 的人可能需要服用药物。血压以及其他因素（如年龄、胆固醇及其相互作用）可能会增加某些疾病的风险。当使用二分变量来确定诊断时，如果不考虑与其他变量的相互作用，则可能会选择错误的连续变量阈值。在本文中，我们将比较单一二分法和联合二分法；这是同时优化多个变量切点的过程。模拟研究表明，同时对连续变量进行二分法更能准确地恢复给定的“真实”阈值。
