Evidence map›Paper›PMID 30789892›Full record

ArticlePLoS medicine2019

COSMOS-E: Guidance on conducting systematic reviews and meta-analyses of observational studies of etiology.

Olaf M Dekkers, Jan P Vandenbroucke, Myriam Cevallos, Andrew G Renehan, Douglas G Altman, Matthias Egger

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in PLoS medicine, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 249 papers, 113 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
249citing papers in PubMed, 113 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

249 citing papers in PubMed, 113 syntheses or guidelines pooled it.

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  3. Combo Deals, Junk Meals: A Systematic Review Examining the Healthiness of Foods Promoted on Meal Delivery Apps.Obesity reviews : an official journal of the International Association for the Study of Obesity · 2026
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  16. Per- and poly-fluoroalkyl substances exposure and risk of gastrointestinal cancers: a systematic review and meta-analysis.European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP) · 2025
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189 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

6 authors.

Olaf M DekkersDepartment of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.ORCID 0000-0002-1333-7580
Jan P VandenbrouckeDepartment of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Myriam CevallosInstitute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
Andrew G RenehanManchester Cancer Research Centre, NIHR Manchester Biomedical Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.ORCID 0000-0002-9115-4405
Douglas G AltmanCentre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
Matthias EggerInstitute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.ORCID 0000-0001-7462-5132

Funding

Cancer Research UK 16895
6 · The paper itself

Abstract

backgroundTo our knowledge, no publication providing overarching guidance on the conduct of systematic reviews of observational studies of etiology exists. METHODS AND

findingsConducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology (COSMOS-E) provides guidance on all steps in systematic reviews of observational studies of etiology, from shaping the research question, defining exposure and outcomes, to assessing the risk of bias and statistical analysis. The writing group included researchers experienced in meta-analyses and observational studies of etiology. Standard peer-review was performed. While the structure of systematic reviews of observational studies on etiology may be similar to that for systematic reviews of randomised controlled trials, there are specific tasks within each component that differ. Examples include assessment for confounding, selection bias, and information bias. In systematic reviews of observational studies of etiology, combining studies in meta-analysis may lead to more precise estimates, but such greater precision does not automatically remedy potential bias. Thorough exploration of sources of heterogeneity is key when assessing the validity of estimates and causality.

conclusionAs many reviews of observational studies on etiology are being performed, this document may provide researchers with guidance on how to conduct and analyse such reviews.

Indexed as

Meta-Analysis as TopicSystematic Reviews as TopicHumansObservational Studies as TopicSelection Bias

Identifiers

PMID30789892
PMCPMC6383865

What OpenQuestion holds

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LicenceCC BY
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.