Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis

One of the most common critics leveled against meta-analysis pertains to the issue of publication bias. A publication bias may be encountered if a meta analysis is restricted to the combination of results obtained from studies which have been published. The bias occur when unpublished studies are as...

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Main Authors:	Nik Idris, Nik Ruzni, Sarudin, Norraida
Format:	Conference or Workshop Item
Language:	English English
Published:	2012
Subjects:	Q Science (General)
Online Access:	http://irep.iium.edu.my/25593/ http://irep.iium.edu.my/25593/1/irie_2012_1211.pdf http://irep.iium.edu.my/25593/4/cert_of_participation.pdf

id	iium-25593
recordtype	eprints
spelling	iium-255932012-12-18T02:39:31Z http://irep.iium.edu.my/25593/ Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis Nik Idris, Nik Ruzni Sarudin, Norraida Q Science (General) One of the most common critics leveled against meta-analysis pertains to the issue of publication bias. A publication bias may be encountered if a meta analysis is restricted to the combination of results obtained from studies which have been published. The bias occur when unpublished studies are associated with their outcomes, namely, studies which produced small effects or negative results are more likely not to get published. The most common method used to adjust for publication bias is the Duvall and Tweedie’s Trim and Fill method. The method relies on the scrutiny of one side of a funnel plot for asymmetry which is assumed to be due to publication bias. In most of the studies investigating the performance of this method, binary meta analysis data were used, utilizing the effect size measures such as the odds ratio, or risk relative. The main aim of this study is to evaluate the efficacy of the Trim and Fill method in correcting the publication bias in meta analysis of continuous data with standardized mean difference as the measure of effects. The data used in this study were simulated using R. The characteristics and assigned values of the simulated meta-analysis, namely the size of treatment effects, study variances and the number of primary studies used, were based on a meta-analyses from medical research. Three levels of primary studies ,N, associated with small, medium and large meta analysis are N =10, 30 and 50/100, respectively, and six levels of percentage of missing publications ,x%, were induced, corresponds to high, medium and low degree of bias at 70%/50%, 30%/20% and 10%/5%, respectively. Each combination of meta-analysis generated was replicated 10,000 times. The inverse-variance weighted random effects estimate were computed for both unadjusted and adjusted meta analysis. The assessment of the effect estimates were evaluated in terms of statistical bias and the standard errors for point estimates, and in terms of confidence band coverage for the interval estimates. 2012-02-21 Conference or Workshop Item PeerReviewed application/pdf en http://irep.iium.edu.my/25593/1/irie_2012_1211.pdf application/pdf en http://irep.iium.edu.my/25593/4/cert_of_participation.pdf Nik Idris, Nik Ruzni and Sarudin, Norraida (2012) Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis. In: IIUM Research, Invention and Innovation Exhibition, IRIIE 2012, 21-22 February 2012, Cultural Activity Centre (CAC) and KAED Gallery, IIUM. (Unpublished)
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English English
topic	Q Science (General)
spellingShingle	Q Science (General) Nik Idris, Nik Ruzni Sarudin, Norraida Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
description	One of the most common critics leveled against meta-analysis pertains to the issue of publication bias. A publication bias may be encountered if a meta analysis is restricted to the combination of results obtained from studies which have been published. The bias occur when unpublished studies are associated with their outcomes, namely, studies which produced small effects or negative results are more likely not to get published. The most common method used to adjust for publication bias is the Duvall and Tweedie’s Trim and Fill method. The method relies on the scrutiny of one side of a funnel plot for asymmetry which is assumed to be due to publication bias. In most of the studies investigating the performance of this method, binary meta analysis data were used, utilizing the effect size measures such as the odds ratio, or risk relative. The main aim of this study is to evaluate the efficacy of the Trim and Fill method in correcting the publication bias in meta analysis of continuous data with standardized mean difference as the measure of effects. The data used in this study were simulated using R. The characteristics and assigned values of the simulated meta-analysis, namely the size of treatment effects, study variances and the number of primary studies used, were based on a meta-analyses from medical research. Three levels of primary studies ,N, associated with small, medium and large meta analysis are N =10, 30 and 50/100, respectively, and six levels of percentage of missing publications ,x%, were induced, corresponds to high, medium and low degree of bias at 70%/50%, 30%/20% and 10%/5%, respectively. Each combination of meta-analysis generated was replicated 10,000 times. The inverse-variance weighted random effects estimate were computed for both unadjusted and adjusted meta analysis. The assessment of the effect estimates were evaluated in terms of statistical bias and the standard errors for point estimates, and in terms of confidence band coverage for the interval estimates.
format	Conference or Workshop Item
author	Nik Idris, Nik Ruzni Sarudin, Norraida
author_facet	Nik Idris, Nik Ruzni Sarudin, Norraida
author_sort	Nik Idris, Nik Ruzni
title	Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
title_short	Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
title_full	Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
title_fullStr	Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
title_full_unstemmed	Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
title_sort	assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis
publishDate	2012
url	http://irep.iium.edu.my/25593/ http://irep.iium.edu.my/25593/1/irie_2012_1211.pdf http://irep.iium.edu.my/25593/4/cert_of_participation.pdf
first_indexed	2023-09-18T20:38:08Z
last_indexed	2023-09-18T20:38:08Z
_version_	1777409184111788032

Assessing the efficacy of the trim and fill method in adjusting for publication bias in meta analysis

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