title: Inference for correlated effect sizes using multiple univariate meta-analyses.
abstract: Multivariate meta-analysis, which involves jointly analyzing multiple and correlated outcomes from separate studies, has received a great deal of attention. One reason to prefer the multivariate approach is its ability to account for the dependence between multiple estimates from the same study. However, nearly all the existing methods for analyzing multivariate meta-analytic data require the knowledge of the within-study correlations, which are usually unavailable in practice. We propose a simple non-iterative method that can be used for the analysis of multivariate meta-analysis datasets, that has no convergence problems, and does not require the use of within-study correlations. Our approach uses standard univariate methods for the marginal effects but also provides valid joint inference for multiple parameters. The proposed method can directly handle missing outcomes under missing completely at random assumption. Simulation studies show that the proposed method provides unbiased estimates, well-estimated standard errors, and confidence intervals with good coverage probability. Furthermore, the proposed method is found to maintain high relative efficiency compared with conventional multivariate meta-analyses where the within-study correlations are known. We illustrate the proposed method through two real meta-analyses where functions of the estimated effects are of interest.
authors.affiliation: Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, U.S.A.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Division of Biostatistics, University of Texas School of Public Health, 1200 Pressler St, Houston, Texas 77030, U.S.A.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Division of Biostatistics, University of Texas School of Public Health, 1200 Pressler St, Houston, Texas 77030, U.S.A.
authors.forename: Chuan
authors.initials: C
authors.lastname: Hong
authors.affiliation: MRC Biostatistics Unit, Cambridge, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge CB2 0SR, U.K.
authors.forename: Dan
authors.initials: D
authors.lastname: Jackson
mesh_terms: D003627:Data Interpretation, Statistical; D006801:Humans; D015201:Meta-Analysis as Topic; D015233:Models, Statistical; D015999:Multivariate Analysis; D013223:Statistics as Topic / Q000379:methods*
keywords: method of moments; multivariate meta-analysis; non-iterative method; singular estimated covariance matrix; within-study correlation