TY - JOUR
AU - The OpenSAFELY Collaborative
AU - Wong, Angel Y.S.
AU - Tomlinson, Laurie A.
AU - Brown, Jeremy P.
AU - Elson, William
AU - Walker, Alex J.
AU - Schultze, Anna
AU - Morton, Caroline E.
AU - Evans, David
AU - Inglesby, Peter
AU - Mackenna, Brian
AU - Bhaskaran, Krishnan
AU - Rentsch, Christopher T.
AU - Powell, Emma
AU - Williamson, Elizabeth
AU - Croker, Richard
AU - Bacon, Sebastian C.J.
AU - Hulme, William
AU - Bates, Chris J.
AU - Curtis, Helen J.
AU - Mehrkar, Amir
AU - Cockburn, Jonathan
AU - McDonald, Helen I.
AU - Mathur, Rohini
AU - Wing, Kevin
AU - Forbes, Harriet
AU - Eggo, Rosalind M.
AU - Evans, Stephen J.W.
AU - Smeeth, Liam
AU - Goldacre, Ben
AU - Douglas, Ian J.
PY - 2021
DA - October
TI - Association between warfarin and COVID-19-related outcomes compared with direct oral anticoagulants: population-based cohort study
JO - Journal of Hematology and Oncology
VL - 14
DO - https://doi.org/10.1186/s13045-021-01185-0
AB - Background: Thromboembolism 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. Methods: On 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. Results: A 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)]. Conclusions: Overall, this study shows no evidence of harmful effects of warfarin on severe COVID-19 disease.
PB - Springer Nature
UR - https://www.research.ed.ac.uk/en/publications/31698be8-4a71-43ca-8167-f4abc4c5e64e
KW - Coronavirus (COVID-19)
ER