Dicotomización de variables continuas en modelos de regresión logística / Dichotomization of continuous variables in logistic regression models

RESUMO

It is highly to observe in the biomedical literature that the continuous variables such as systolic blood pressure and cholesterol are dichotomized and used in such manner in a given statistical analysis. The consequences of such transformation can be very varied. In this article, how the dichotomization of a continuous exposure variable affects the quality of the prediction of a response using the logistic regression is examined. One can conclude that, in almost all the studied simulation, the percentages of misclassification can increase deastically, reaching over there times the probability of misclassification of the ones using the original variable. Therefore, we recommended to avoid dichotomization