Two-sample empirical likelihood method for right censored data
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Leonora Pahirko
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Janis Valeinis
Abstract
In this paper, a two-sample empirical likelihood method for right censored data is established. This method allows for comparisons between various functionals of survival distributions, such as mean lifetimes, survival probabilities at a fixed time, restricted mean survival times, and other parameters of interest. It is demonstrated that under some regularity conditions, the scaled empirical likelihood statistic converges to a chi-squared distributed random variable with one degree of freedom. A consistent estimator for the scaling constant is proposed, involving the jackknife estimator of the asymptotic variance of the Kaplan-Meier integral. A simulation study is carried out to investigate the coverage accuracy of confidence intervals. Finally, two real datasets are analyzed to illustrate the application of the proposed method.
Funding source: European Social Fund
Award Identifier / Grant number: No.8.2.2.0/20/1/006
Acknowledgments
We thank Viktorija Ulanova for granting us permission to use her research data (project identification No. lzp-2020/1–0050) for the illustration purposes. We also sincerely thank the reviewers for their time, effort, and constructive feedback on the manuscript.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission. J.V. conceptualized the research problem, developed the theoretical framework, supervised the study, and provided critical revisions. L.P. developed the theoretical framework, conducted the formal proofs, wrote the manuscript, and performed coding, simulations, and practical data analyses. D.J. performed coding, simulations, and practical data analyses.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: European Social Fund No.8.2.2.0/20/1/006.
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Data availability: The raw data are available upon request from the corresponding author or in the GitHub repository: https://github.com/LU-SPDAL/publications/tree/main/2SAMP_EL_SURV.
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Software availability: All R code used in this study is available in the GitHub repository: https://github.com/LU-SPDAL/publications/tree/main/2SAMP_EL_SURV.
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