Evidence map›Paper›PMID 21559325›Full record

SynthesisPLoS medicine2011

Meta-analyses of adverse effects data derived from randomised controlled trials as compared to observational studies: methodological overview.

Su Golder, Yoon K Loke, Martin Bland

Abstract readComparative StudyMeta-AnalysisReview
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in PLoS medicine, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 121 papers, 54 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
121citing papers in PubMed, 54 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

121 citing papers in PubMed, 54 syntheses or guidelines pooled it.

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  12. Surgical treatment of proximal humerus fractures: a systematic review and meta-analysis.European journal of orthopaedic surgery & traumatology : orthopedie traumatologie · 2023
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  18. Evidence of the Importance of Dietary Habits Regarding Depressive Symptoms and Depression.International journal of environmental research and public health · 2020
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  19. Water for preventing urinary stones.The Cochrane database of systematic reviews · 2020
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61 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Su GolderCentre for Reviews and Dissemination, University of York, York, United Kingdom. su.golder@york.ac.uk
Yoon K Loke
Martin Bland

Funding

Medical Research Council G0601692
6 · The paper itself

Abstract

backgroundThere is considerable debate as to the relative merits of using randomised controlled trial (RCT) data as opposed to observational data in systematic reviews of adverse effects. This meta-analysis of meta-analyses aimed to assess the level of agreement or disagreement in the estimates of harm derived from meta-analysis of RCTs as compared to meta-analysis of observational studies. METHODS AND

findingsSearches were carried out in ten databases in addition to reference checking, contacting experts, citation searches, and hand-searching key journals, conference proceedings, and Web sites. Studies were included where a pooled relative measure of an adverse effect (odds ratio or risk ratio) from RCTs could be directly compared, using the ratio of odds ratios, with the pooled estimate for the same adverse effect arising from observational studies. Nineteen studies, yielding 58 meta-analyses, were identified for inclusion. The pooled ratio of odds ratios of RCTs compared to observational studies was estimated to be 1.03 (95% confidence interval 0.93-1.15). There was less discrepancy with larger studies. The symmetric funnel plot suggests that there is no consistent difference between risk estimates from meta-analysis of RCT data and those from meta-analysis of observational studies. In almost all instances, the estimates of harm from meta-analyses of the different study designs had 95% confidence intervals that overlapped (54/58, 93%). In terms of statistical significance, in nearly two-thirds (37/58, 64%), the results agreed (both studies showing a significant increase or significant decrease or both showing no significant difference). In only one meta-analysis about one adverse effect was there opposing statistical significance.

conclusionsEmpirical evidence from this overview indicates that there is no difference on average in the risk estimate of adverse effects of an intervention derived from meta-analyses of RCTs and meta-analyses of observational studies. This suggests that systematic reviews of adverse effects should not be restricted to specific study types. Please see later in the article for the Editors' Summary.

Indexed as

Meta-Analysis as TopicObservationRandomized Controlled Trials as TopicData Interpretation, StatisticalHumansOdds RatioResearch DesignRisk AssessmentTreatment Outcome

Identifiers

PMID21559325
PMCPMC3086872

What OpenQuestion holds

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Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.