How important are comprehensive literature searches and the assessment of trial quality in systematic reviews? Empirical study.

By Matthias Egger, Peter Jüni, C. Bartlett, F. Holenstein, J. Sterne. Health Technology Assessment, 2003

1,067 citations recorded by the source corpus.

Subfields: Economics and Econometrics, Public Health, Environmental and Occupational Health, Statistics and Probability

View Paper: https://www.semanticscholar.org/paper/be7f7feb76f845bd1771d2c4827dcef9b85a1160

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Citations in the corpus

Dissemination and publication of research findings: an updated review of related biases. (2010, methodology): “Tang and Liu (2000)444 A sample size-based linear regression in which the estimate of the effect size is regressed against the square root of the average number of participants in the two trial groups, weighted by the sample size Tang and Liu (2000) mentioned that the interpretation of the intercept”
Resilience and Burnout in Child Protection Social Work: Individual and Organisational Themes from a Systematic Literature Review (2015, background): “Extending the search to this type of grey literature reduces the potential for publication bias (Burdett et al, 2003) although it is recognised that this is less of an issue for social work than for some other areas of study (Egger et al, 2003, Taylor, Dempster and Donnelly, 2007).”
Funnel Plots in Meta-analysis (2004, result): “Smaller studies are, on average, conducted and analyzed with less methodological rigor than larger studies (Egger et al. 2003), so asymmetry may also result from the overestimation of treatment effects in smaller studies of lower methodological quality (bottom graph of figure 1).”
Thrombophilia in pregnancy: a systematic review (2006, background): “We restricted this review to studies that were published in English.”
Interventions targeting social isolation in older people: a systematic review (2011, background): “Limiting study eligibility to those published in English may also have introduced bias [86], although this decision was made for pragmatic reasons.”
A Comprehensive Meta-Analysis of Triple P-Positive Parenting Program Using Hierarchical Linear Modeling: Effectiveness and Moderating Variables (2008, background): “Concurrently, Egger et al. (2003), analyzing 159 systematic reviews, found a bias toward more beneficial intervention effects in inadequately concealed and unblinded trials.”
Cochrane handbook for systematic reviews of interventions. Version 5.1.0 [updated March 2011]. The Cochrane Collaboration (2011, background): “In other areas of medicine, however, it is essential to broaden the search to include unpublished trials, for example in oncology and in complementary medicine (Egger et al 2003).”
Publication bias in the social sciences: Unlocking the file drawer (2014, background): “, dissertations, working papers, conference papers, human subjects registries) may confound strength of results with research quality (7).”
Influence of Reported Study Design Characteristics on Intervention Effect Estimates From Randomized, Controlled Trials (2012, background): “The study by Egger and associates (2) was based on quality assessments by authors of the included Cochrane reviews, which were generally performed in duplicate by 2 observers.”
Association of funding and conclusions in randomized drug trials: a reflection of treatment effect or adverse events? (2003, neutral): “Sample size Median (range)* 120 (10-14 046) 55 (12-497) 178 (13-82 892) 110 (11-3575)”