Evidence map›Paper›PMID 32909033›Full record

ArticleJournal of the American Medical Informatics Association : JAMIA2020

Principles of Large-scale Evidence Generation and Evaluation across a Network of Databases (LEGEND).

Martijn J Schuemie, Patrick B Ryan, Nicole Pratt, RuiJun Chen, Seng Chan You, Harlan M Krumholz, David Madigan, George Hripcsak, Marc A Suchard

Abstract read
In one paragraph

Article in Journal of the American Medical Informatics Association : JAMIA, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 36 papers.

0numbers the graph read from it
0cells of the map it votes in
36citing papers in PubMed
–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

36 citing papers in PubMed.

  1. Evaluating large-scale propensity score adjustment when sample size is small.Journal of the American Medical Informatics Association : JAMIA · 2026
    Article
  2. Article
  3. Article
  4. When evidence meets artificial intelligence.Lancet regional health. Americas · 2026
    Review
  5. Trust in Observational Research.Journal of the American College of Cardiology · 2026
    Article
  6. Article
  7. Article
  8. Article
  9. Assessing Covariate Balance with Small Sample Sizes.medRxiv : the preprint server for health sciences · 2025
    Article
  10. Article
  11. Article
  12. Review
  13. Article
  14. Article
  15. Article
  16. Review
  17. Article
  18. Review
  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.

Martijn J SchuemieEpidemiology Analytics, Janssen Research and Development, Titusville, New Jersey, USA.
Patrick B RyanEpidemiology Analytics, Janssen Research and Development, Titusville, New Jersey, USA.
Nicole PrattQuality Use of Medicines and Pharmacy Research Centre, University of South Australia, Adelaide, South Australia, Australia.
RuiJun ChenDepartment of Biomedical Informatics, Columbia University Medical Center, New York, New York, USA.
Seng Chan YouDepartment of Biomedical Informatics, Ajou University School of Medicine, Suwon, Korea.
Harlan M KrumholzDepartment of Medicine, Yale University School of Medicine, New Haven, California, USA.
David MadiganDepartment of Statistics, Columbia University, New York, New York, USA.
George HripcsakDepartment of Biomedical Informatics, Columbia University Medical Center, New York, New York, USA.
Marc A SuchardDepartment of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, California, USA.

Funding

Yale Clinical and Translational Science Award (U Component)UL1TR001863 · NCATS · YALE UNIVERSITY · PI John H. Krystal, LUCILA OHNO-MACHADO · 2016 to 2026
$102.9M
DISCOVERING AND APPLYING KNOWLEDGE IN CLINICAL DATABASESR01LM006910 · NLM · COLUMBIA UNIVERSITY HEALTH SCIENCES · PI HRIPCSAK, GEORGE M · 2000 to 2023
$10.6M
NCATS NIH HHS UL1 TR001863NLM NIH HHS R01 LM006910
6 · The paper itself

Abstract

Evidence derived from existing health-care data, such as administrative claims and electronic health records, can fill evidence gaps in medicine. However, many claim such data cannot be used to estimate causal treatment effects because of the potential for observational study bias; for example, due to residual confounding. Other concerns include P hacking and publication bias. In response, the Observational Health Data Sciences and Informatics international collaborative launched the Large-scale Evidence Generation and Evaluation across a Network of Databases (LEGEND) research initiative. Its mission is to generate evidence on the effects of medical interventions using observational health-care databases while addressing the aforementioned concerns by following a recently proposed paradigm. We define 10 principles of LEGEND that enshrine this new paradigm, prescribing the generation and dissemination of evidence on many research questions at once; for example, comparing all treatments for a disease for many outcomes, thus preventing publication bias. These questions are answered using a prespecified and systematic approach, avoiding P hacking. Best-practice statistical methods address measured confounding, and control questions (research questions where the answer is known) quantify potential residual bias. Finally, the evidence is generated in a network of databases to assess consistency by sharing open-source analytics code to enhance transparency and reproducibility, but without sharing patient-level information. Here we detail the LEGEND principles and provide a generic overview of a LEGEND study. Our companion paper highlights an example study on the effects of hypertension treatments, and evaluates the internal and external validity of the evidence we generate.

Indexed as

Computer Communication NetworksDatabases, FactualMeta-Analysis as TopicAntihypertensive AgentsConfidence IntervalsData Interpretation, StatisticalHumansHypertensionObservationPropensity ScoreRandomized Controlled Trials as TopicTreatment OutcomeAntihypertensive Agentsempirical calibrationobservational studiesopen sciencetreatment effects

Identifiers

PMID32909033
PMCPMC7481029

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.