Evidence map›Paper›PMID 35537752›Full record

ArticleBMJ (Clinical research ed.)2022

Validity of data extraction in evidence synthesis practice of adverse events: reproducibility study.

Chang Xu, Tianqi Yu, Luis Furuya-Kanamori, Lifeng Lin, Liliane Zorzela, Xiaoqin Zhou, Hanming Dai, Yoon Loke, Sunita Vohra

Abstract read
In one paragraph

Article in BMJ (Clinical research ed.), 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
40citing papers in PubMed, 5 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

40 citing papers in PubMed, 5 syntheses or guidelines pooled it.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Pooled it
  5. Pooled it
  6. Article
  7. Article
  8. Article
  9. Article
  10. Article
  11. Article
  12. Article
  13. Article
  14. Article
  15. Organic Pollutants and Risk of Type 2 Diabetes: A Systematic Review and Meta-analysis.Mayo Clinic proceedings. Innovations, quality & outcomes · 2026
    Article
  16. Article
  17. Article
  18. Article
  19. Article
  20. Article
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

9 authors.

Chang XuKey Laboratory of Population Health Across-life Cycle, Ministry of Education of the People's Republic of China, Anhui Medical University, Anhui, China.
Tianqi YuChinese Evidence-based Medicine Centre, West China Hospital, Sichuan University, Chengdu, China.
Luis Furuya-KanamoriUQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia.
Lifeng LinDepartment of Statistics, Florida State University, Tallahassee, FL, USA.
Liliane ZorzelaDepartment of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, AB, Canada.
Xiaoqin ZhouMental Health Centre, West China Hospital of Sichuan University, Chengdu, China.
Hanming DaiMental Health Centre, West China Hospital of Sichuan University, Chengdu, China.
Yoon LokeNorwich Medical School, University of East Anglia, Norwich, UK.
Sunita VohraDepartment of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, AB, Canada svohra@ualberta.ca.ORCID 0000-0002-6210-7933

Funding

Statistical Methods and Software for Multivariate Meta-analysisR01LM012982 · NLM · UNIVERSITY OF MINNESOTA · PI LIN, LIFENG, SIEGEL, LIANNE · 2019 to 2022
$1.3M
Joint modeling of continuous and binary data in meta-analysisR03MH128727 · NIMH · UNIVERSITY OF ARIZONA · PI LIN, LIFENG · 2022 to 2023
$146k
NIMH NIH HHS R03 MH128727NLM NIH HHS R01 LM012982
6 · The paper itself

Abstract

objectivesTo investigate the validity of data extraction in systematic reviews of adverse events, the effect of data extraction errors on the results, and to develop a classification framework for data extraction errors to support further methodological research.

designReproducibility study. DATA SOURCES: PubMed was searched for eligible systematic reviews published between 1 January 2015 and 1 January 2020. Metadata from the randomised controlled trials were extracted from the systematic reviews by four authors. The original data sources (eg, full text and ClinicalTrials.gov) were then referred to by the same authors to reproduce the data used in these meta-analyses. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Systematic reviews were included when based on randomised controlled trials for healthcare interventions that reported safety as the exclusive outcome, with at least one pair meta-analysis that included five or more randomised controlled trials and with a 2×2 table of data for event counts and sample sizes in intervention and control arms available for each trial in the meta-analysis.

main outcome measuresThe primary outcome was data extraction errors summarised at three levels: study level, meta-analysis level, and systematic review level. The potential effect of such errors on the results was further investigated.

results201 systematic reviews and 829 pairwise meta-analyses involving 10 386 randomised controlled trials were included. Data extraction could not be reproduced in 1762 (17.0%) of 10 386 trials. In 554 (66.8%) of 829 meta-analyses, at least one randomised controlled trial had data extraction errors; 171 (85.1%) of 201 systematic reviews had at least one meta-analysis with data extraction errors. The most common types of data extraction errors were numerical errors (49.2%, 867/1762) and ambiguous errors (29.9%, 526/1762), mainly caused by ambiguous definitions of the outcomes. These categories were followed by three others: zero assumption errors, misidentification, and mismatching errors. The impact of these errors were analysed on 288 meta-analyses. Data extraction errors led to 10 (3.5%) of 288 meta-analyses changing the direction of the effect and 19 (6.6%) of 288 meta-analyses changing the significance of the P value. Meta-analyses that had two or more different types of errors were more susceptible to these changes than those with only one type of error (for moderate changes, 11 (28.2%) of 39

conclusionSystematic reviews of adverse events potentially have serious issues in terms of the reproducibility of the data extraction, and these errors can mislead the conclusions. Implementation guidelines are urgently required to help authors of future systematic reviews improve the validity of data extraction.

Indexed as

Reproducibility of ResultsData MiningHumansMeta-Analysis as TopicRandomized Controlled Trials as TopicSystematic Reviews as Topic

Identifiers

PMID35537752
PMCPMC9086856

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
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.