RT Journal Article T1 Evaluation of surrogate endpoints using information-theoretic measure of association based on Havrda and Charvat entropy A1 Pardo Llorente, María del Carmen A1 Zhao, Qian A1 Jin, Hua A1 Lu, Ying AB Surrogate endpoints have been used to assess the efficacy of a treatment and can potentially reduce the duration and/or number of required patients for clinical trials. Using information theory, Alonso et al. (2007) proposed a unified framework based on Shannon entropy, a new definition of surrogacy that departed from the hypothesis testing framework. In this paper, a new family of surrogacy measures under Havrda and Charvat (H-C) entropy is derived which contains Alonso’s definition as a particular case. Furthermore, we extend our approach to a new model based on the information-theoretic measure of association for a longitudinally collected continuous surrogate endpoint for a binary clinical endpoint of a clinical trial using H-C entropy. The new model is illustrated through the analysis of data from a completed clinical trial. It demonstrates advantages of H-C entropy-based surrogacy measures in the evaluation of scheduling longitudinal biomarker visits for a phase 2 randomized controlled clinical trial for treatment of multiple sclerosis. PB MDPI SN 2227-7390 YR 2022 FD 2022-01-31 LK https://hdl.handle.net/20.500.14352/73049 UL https://hdl.handle.net/20.500.14352/73049 LA eng DS Docta Complutense RD 14 jul 2025