Empirical likelihood meta analysis with publication bias correction under Copas-like selection model

Fuente: arXiv
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Main Authors: Li, Mengke, Liu, Yukun, Li, Pengfei, Qin, Jing
Format: Preprint
Published: 2025
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author Li, Mengke
Liu, Yukun
Li, Pengfei
Qin, Jing
author_facet Li, Mengke
Liu, Yukun
Li, Pengfei
Qin, Jing
contents Meta analysis is commonly-used to synthesize multiple results from individual studies. However, its validation is usually threatened by publication bias and between-study heterogeneity, which can be captured by the Copas selection model. Existing inference methods under this model are all based on conditional likelihood and may not be fully efficient. In this paper, we propose a full likelihood approach to meta analysis by integrating the conditional likelihood and a marginal semi-parametric empirical likelihood under a Copas-like selection model. We show that the maximum likelihood estimators (MLE) of all the underlying parameters have a jointly normal limiting distribution, and the full likelihood ratio follows an asymptotic central chisquare distribution. Our simulation results indicate that compared with the conditional likelihood method, the proposed MLEs have smaller mean squared errors and the full likelihood ratio confidence intervals have more accurate coverage probabilities. A real data example is analyzed to show the advantages of the full likelihood method over the conditional likelihood method.
format Preprint
id arxiv_https___arxiv_org_abs_2507_13615
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Empirical likelihood meta analysis with publication bias correction under Copas-like selection model
Li, Mengke
Liu, Yukun
Li, Pengfei
Qin, Jing
Methodology
Meta analysis is commonly-used to synthesize multiple results from individual studies. However, its validation is usually threatened by publication bias and between-study heterogeneity, which can be captured by the Copas selection model. Existing inference methods under this model are all based on conditional likelihood and may not be fully efficient. In this paper, we propose a full likelihood approach to meta analysis by integrating the conditional likelihood and a marginal semi-parametric empirical likelihood under a Copas-like selection model. We show that the maximum likelihood estimators (MLE) of all the underlying parameters have a jointly normal limiting distribution, and the full likelihood ratio follows an asymptotic central chisquare distribution. Our simulation results indicate that compared with the conditional likelihood method, the proposed MLEs have smaller mean squared errors and the full likelihood ratio confidence intervals have more accurate coverage probabilities. A real data example is analyzed to show the advantages of the full likelihood method over the conditional likelihood method.
title Empirical likelihood meta analysis with publication bias correction under Copas-like selection model
topic Methodology
url https://arxiv.org/abs/2507.13615