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Evaluating markers for treatment selection based on survival time
Author(s) -
Song Xiao,
Zhou XiaoHua
Publication year - 2011
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.4258
Subject(s) - covariate , nonparametric statistics , estimator , selection (genetic algorithm) , feature selection , population , computer science , biomarker , survival analysis , statistics , medicine , econometrics , oncology , machine learning , mathematics , biology , biochemistry , environmental health
For many medical conditions, several treatment options may be available for treating patients. We consider evaluating markers based on a simple treatment selection policy that incorporates information on the patient's marker value. For example, colon cancer patients may be treated by surgery alone or surgery plus chemotherapy. The c‐myc gene expression level may be used as a biomarker for treatment selection. Although traditional regression methods may assess the effect of the marker and treatment on outcomes, it is more appealing to quantify directly the potential impact on the population of using the marker to select treatment. A useful tool is the selection impact (SI) curve proposed by Song and Pepe for binary outcomes ( Biometrics 2004; 60:874–883). However, the current SI method does not deal with continuous outcomes, nor does it allow to adjust for other covariates that are important for treatment selection. In this paper, we extend the SI curve for general outcomes, with a specific focus on survival time. We further propose the covariate‐specific SI curve to incorporate covariate information in treatment selection. Nonparametric and semiparametric estimators are developed accordingly. We show that the proposed estimators are consistent and asymptotically normal. The performance is assessed by simulation studies and illustrated through an application to data from a cancer clinical trial. Copyright © 2011 John Wiley & Sons, Ltd.