title: Some general points in estimating heterogeneity variance with the DerSimonian-Laird estimator.
abstract: In this paper we consider estimating heterogeneity variance with the DerSimonian-Laird (DSL) estimator as typically used in meta-analysis. In its general form the DSL estimator requires inverse population-averaged study-specific variances as weights, in which case the estimator is unbiased. It has become common practice, however, to use estimates of the study-specific variances instead of their population-averaged versions. This can lead to considerable bias. Simulations illustrate these findings.
authors.affiliation: Department of Epidemiology, Free University Berlin, Haus 562, Fabeckstr. 60-62, 14195 Berlin, Germany. boehning@zedat.fu-berlin.de
authors.forename: Dankmar
authors.initials: D
authors.lastname: Böhning
authors.forename: Uwe
authors.initials: U
authors.lastname: Malzahn
authors.forename: Ekkehart
authors.initials: E
authors.lastname: Dietz
authors.forename: Peter
authors.initials: P
authors.lastname: Schlattmann
authors.forename: Chukiat
authors.initials: C
authors.lastname: Viwatwongkasem
authors.forename: Annibale
authors.initials: A
authors.lastname: Biggeri