Evidence map›Paper›PMID 27531725›Full record

ArticleBMJ open2016

Impact of including or excluding both-armed zero-event studies on using standard meta-analysis methods for rare event outcome: a simulation study.

Ji Cheng, Eleanor Pullenayegum, John K Marshall, Alfonso Iorio, Lehana Thabane

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ open, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 66 papers, 32 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
66citing papers in PubMed, 32 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

66 citing papers in PubMed, 32 syntheses or guidelines pooled it.

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  9. Normothermic Regional Perfusion in Controlled Donation After Circulatory Death Liver Transplantation: A Systematic Review and Meta-Analysis.Transplant international : official journal of the European Society for Organ Transplantation · 2024
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  11. Efficacy and safety of selective serotonin reuptake inhibitors in COVID-19 management: a systematic review and meta-analysis.Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases · 2023
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  18. Radiofrequency atrial fibrillation ablation with irrigated tip catheter using remote magnetic navigation compared with conventional manual method.Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing · 2021
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6 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

5 authors.

Ji ChengDepartment of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada.
Eleanor PullenayegumDepartment of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada The Hospital for Sick Children, Toronto, Ontario, Canada.
John K MarshallDepartment of Medicine, McMaster University, Hamilton, Ontario, Canada.
Alfonso IorioDepartment of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada Department of Medicine, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0002-3331-8766
Lehana ThabaneDepartment of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesThere is no consensus on whether studies with no observed events in the treatment and control arms, the so-called both-armed zero-event studies, should be included in a meta-analysis of randomised controlled trials (RCTs). Current analytic approaches handled them differently depending on the choice of effect measures and authors' discretion. Our objective is to evaluate the impact of including or excluding both-armed zero-event (BA0E) studies in meta-analysis of RCTs with rare outcome events through a simulation study.

methodWe simulated 2500 data sets for different scenarios varying the parameters of baseline event rate, treatment effect and number of patients in each trial, and between-study variance. We evaluated the performance of commonly used pooling methods in classical meta-analysis-namely, Peto, Mantel-Haenszel with fixed-effects and random-effects models, and inverse variance method with fixed-effects and random-effects models-using bias, root mean square error, length of 95% CI and coverage.

resultsThe overall performance of the approaches of including or excluding BA0E studies in meta-analysis varied according to the magnitude of true treatment effect. Including BA0E studies introduced very little bias, decreased mean square error, narrowed the 95% CI and increased the coverage when no true treatment effect existed. However, when a true treatment effect existed, the estimates from the approach of excluding BA0E studies led to smaller bias than including them. Among all evaluated methods, the Peto method excluding BA0E studies gave the least biased results when a true treatment effect existed.

conclusionsWe recommend including BA0E studies when treatment effects are unlikely, but excluding them when there is a decisive treatment effect. Providing results of including and excluding BA0E studies to assess the robustness of the pooled estimated effect is a sensible way to communicate the results of a meta-analysis when the treatment effects are unclear.

Indexed as

Computer SimulationMeta-Analysis as TopicRandomized Controlled Trials as TopicData Interpretation, StatisticalHumansboth-armed zero-eventmeta-analysisrare event outcomesimulation

Identifiers

PMID27531725
PMCPMC5013416

What OpenQuestion holds

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LicenceCC BY-NC
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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.