Abstract
Predictive and prognostic biomarkers are increasingly important in clinical research and practice. Biomarker studies are frequently embedded in randomized clinical trials with biospecimens collected at baseline and assayed for biomarkers, either in real time or retrospectively. This article proposes efficient estimation strategies for two study settings in terms of biomarker ascertainment: a complete-data setting in which the biomarker is measured for all subjects in the trial, and a two-phase sampling design in which the biomarker is measured retrospectively for a random subsample of subjects selected in an outcome-dependent fashion. In both settings, efficient estimating functions are characterized using semiparametric theory and approximated using data-adaptive machine learning methods, leading to estimators that are consistent, asymptotically normal and (approximately) efficient under general conditions. The proposed methods are evaluated in simulation studies and applied to real data from two biomarker studies, one in each setting.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
