COMPARING THE BIVARIATE EFFECTS OF TOXICITY AND EFFICACY OF TREATMENTS

Medical studies often involve comparing the toxicity and efficacy of d rugs. Separately evaluating toxicity and efficacy, the usual practice, does not correspond to how doctors manage patients and does not use t he information provided in their bivariate relationship. This paper pr esents methods for analysing the bivariate data. One method is based o n assessing the benefit for patient values to lie in different regions of the toxicity-efficacy plane. A second method includes patient thre sholds for tolerating drugs. We propose dividing the toxicity-efficacy plane into regions where patients are likely to tolerate the drug. Se veral statistics are defined on these regions for measuring the toxic- therapeutic relationship, and the bootstrap is proposed for estimating their variances. We illustrate with treatment information available o n rheumatoid arthritis patients.