Evidence map›Paper›PMID 34666811›Full record

ArticleJournal of hematology & oncology2021

Association between warfarin and COVID-19-related outcomes compared with direct oral anticoagulants: population-based cohort study.

OpenSAFELY Collaborative, Angel Y S Wong, Laurie A Tomlinson, Jeremy P Brown, William Elson, Alex J Walker, Anna Schultze, Caroline E Morton, David Evans, Peter Inglesby and 21 more

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Journal of hematology & oncology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed
1.0field-weighted citation impact, top 21% of its field
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

7 citing papers in PubMed, 15 citations in OpenAlex.

  1. Article
  2. Review
  3. Article
  4. Article
  5. Role of Cytochrome P450 2C9 in COVID-19 Treatment: Current Status and Future Directions.European journal of drug metabolism and pharmacokinetics · 2023
    Review
  6. ISTH guidelines for antithrombotic treatment in COVID-19.Journal of thrombosis and haemostasis : JTH · 2022
    Article
  7. Review
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

31 authors at 3 institutions in 1 country.

OpenSAFELY Collaborative
Angel Y S WongFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK. Angel.Wong@lshtm.ac.uk.ORCID 0000-0002-8618-7333
Laurie A TomlinsonFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Jeremy P BrownFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
William ElsonFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Alex J WalkerThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Anna SchultzeFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Caroline E MortonThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
David EvansThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Peter InglesbyThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Brian MacKennaThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Krishnan BhaskaranFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Christopher T RentschFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Emma PowellFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Elizabeth WilliamsonFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Richard CrokerThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Seb BaconThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
William HulmeThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Chris BatesTPP, TPP House, Horsforth, Leeds, UK.
Helen J CurtisThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Amir MehrkarThe DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Jonathan CockburnTPP, TPP House, Horsforth, Leeds, UK.
Helen I McDonaldFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Rohini MathurFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Kevin WingFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Harriet ForbesFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Rosalind M EggoFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Stephen J W EvansFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Liam SmeethFaculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Ben Goldacre *The DataLab, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Ian J Douglas *Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
University of Oxford · GBLondon School of Hygiene & Tropical Medicine · GBUniversity of Liverpool · GB

Funding

British Heart Foundation FS/19/19/34175Medical Research Council MC_PC_20058Medical Research Council MC_PC_20059Medical Research Council MR/S003975/1Medical Research Council MR/V015737/1
6 · The paper itself

Abstract

backgroundThromboembolism has been reported as a consequence of severe COVID-19. Although warfarin is a commonly used anticoagulant, it acts by antagonising vitamin K, which is low in patients with severe COVID-19. To date, the clinical evidence on the impact of regular use of warfarin on COVID-19-related thromboembolism is lacking.

methodsOn behalf of NHS England, we conducted a population-based cohort study investigating the association between warfarin and COVID-19 outcomes compared with direct oral anticoagulants (DOACs). We used the OpenSAFELY platform to analyse primary care data and pseudonymously linked SARS-CoV-2 antigen testing data, hospital admissions and death records from England. We used Cox regression to estimate hazard ratios (HRs) for COVID-19-related outcomes comparing warfarin with DOACs in people with non-valvular atrial fibrillation. We also conducted negative control outcome analyses (being tested for SARS-CoV-2 and non-COVID-19 death) to assess the potential impact of confounding.

resultsA total of 92,339 warfarin users and 280,407 DOAC users were included. We observed a lower risk of all outcomes associated with warfarin versus DOACs [testing positive for SARS-CoV-2, HR 0.73 (95% CI 0.68-0.79); COVID-19-related hospital admission, HR 0.75 (95% CI 0.68-0.83); COVID-19-related deaths, HR 0.74 (95% CI 0.66-0.83)]. A lower risk of negative control outcomes associated with warfarin versus DOACs was also observed [being tested for SARS-CoV-2, HR 0.80 (95% CI 0.79-0.81); non-COVID-19 deaths, HR 0.79 (95% CI 0.76-0.83)].

conclusionsOverall, this study shows no evidence of harmful effects of warfarin on severe COVID-19 disease.

Indexed as

Administration, OralAdolescentAdultAgedAged, 80 and overAnticoagulantsCohort StudiesCOVID-19COVID-19 Drug TreatmentEnglandHumansMiddle AgedSARS-CoV-2ThromboembolismTreatment OutcomeWarfarinAnticoagulantsWarfarinCOVID-19Direct oral anticoagulantsWarfarin

Identifiers

PMID34666811
PMCPMC8525065
OpenAlexW3206857681

What OpenQuestion 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 OpenQuestion graph.