Evidence map›Paper›PMID 40999337›Full record

ArticleBMC medical research methodology2025

Evaluating the properties of the fragility index of meta-analyses.

Aiwen Xing, Xing Xing, Mohammad Hassan Murad, Lifeng Lin

Abstract read
In one paragraph

Article in BMC medical research methodology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed, 1 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

1 citing paper in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
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

4 authors.

Aiwen Xing *Biostatistics and Research Decision Sciences, Merck & Co., Inc, Rahway, NJ, USA.
Xing Xing *Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Mohammad Hassan MuradEvidence-Based Practice Center, Mayo Clinic, Rochester, MN, USA.
Lifeng LinDepartment of Epidemiology and Biostatistics, University of Arizona, 1295 N. Martin Ave., Tucson, AZ, 85724, USA. lifenglin@arizona.edu.

Funding

Statistical Methods and Software for Multivariate Meta-analysisR01LM012982 · NLM · UNIVERSITY OF MINNESOTA · PI LIN, LIFENG, SIEGEL, LIANNE · 2019 to 2022
$1.3M
Advanced Methods and Software for Trial Sequential Analysis in Living Systematic ReviewsR21LM014533 · NLM · UNIVERSITY OF ARIZONA · PI LIN, LIFENG · 2024 to 2025
$364k
Innovative Data Integration Models for Handling Evidence Inconsistency in AD/ADRD ResearchR03AG093555 · NIA · UNIVERSITY OF ARIZONA · PI LIN, LIFENG · 2025 to 2025
$301k
Joint modeling of continuous and binary data in meta-analysisR03MH128727 · NIMH · UNIVERSITY OF ARIZONA · PI LIN, LIFENG · 2022 to 2023
$146k
Arizona Biomedical Research Commission RFGA2023-008-11NIA NIH HHS R03 AG093555NIMH NIH HHS R03 MH128727NLM NIH HHS R01 LM012982NLM NIH HHS R21 LM014533
6 · The paper itself

Abstract

backgroundThe fragility index (FI) has become an increasingly popular supplementary measure for evaluating the robustness of a study's conclusions. While initially developed for individual clinical trials, the FI has been extended to meta-analyses (MAs) of multiple studies. However, the existing literature provides limited insights into the properties of the FI in the context of MAs. This study aims to explore various statistical methods for MAs and assess the improvement in FI of MAs compared to the individual studies they comprise.

methodsWe investigated the empirical distributions of FI and fragility quotient (FQ) using a large database of Cochrane MAs with binary outcomes. The FI of MAs was calculated under different statistical methods, including fixed-effect and random-effects models, with between-study variance estimators (restricted maximum-likelihood and DerSimonian-Laird), alongside Hartung-Knapp-Sidik-Jonkman (HKSJ) confidence interval adjustments. Subgroup analyses were performed to explore the impact of heterogeneity, sample size, and effect measures on fragility. Furthermore, we employed a metric to evaluate the improvement in fragility by comparing the FI of MAs with the FIs of the individual studies they included.

resultsThe median FI was 5 (IQR: 2-11) among 3,758 MAs analyzed, with 29% reporting statistically significant results. Notably, 15% of MAs had an FI of 1, and 54% had an FI ≤ 5. MAs with larger sample sizes or higher [Formula: see text] values, tended to exhibit greater robustness. HKSJ adjustments introduced more uncertainty, yielding more fragile results compared to analyses without these adjustments. Fragility improvement was higher in MAs with considerable heterogeneity.

conclusionsThis study highlights the variability in fragility across MAs and underscores the influence of heterogeneity and statistical methods on FI. Further research is warranted to refine the assessment of fragility and incorporate clinical relevance into these evaluations.

Indexed as

Meta-Analysis as TopicModels, StatisticalData Interpretation, StatisticalHumansResearch DesignEvidence synthesisFragility indexHeterogeneityMeta-analysis

Identifiers

PMID40999337
PMCPMC12465983

What Socratic holds

Textmetadata
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 Socratic graph.