OpenSAFELY

Published Papers

OpenSAFELY: factors associated with COVID-19 death in 17 million patients

July 2020. Abstract: "COVID-19 has rapidly affected mortality worldwide. There is unprecedented urgency to understand who is most at risk of severe outcomes, requiring new approaches for timely analysis of large datasets. Working on behalf of NHS England, here we created OpenSAFELY: a secure health analytics platform covering 40% of all patients in England, holding patient data within the existing data centre of a major primary care electronic health records vendor. Primary care records of 17,278,392 adults were pseudonymously linked to 10,926 COVID-19-related deaths. COVID-19-related death was associated with: being male (hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.53–1.65); older age and deprivation (both with a strong gradient); diabetes; severe asthma; and various other medical conditions. Compared with people with white ethnicity, Black and South Asian people were at higher risk even after adjustment for other factors (HR 1.48, 1.30–1.69 and 1.44, 1.32–1.58, respectively). We have quantified a range of clinical risk factors for COVID-19-related death in the largest cohort study conducted by any country to date. OpenSAFELY is rapidly adding further patients’ records; we will update and extend results regularly."

How to Cite Williamson, E.J., Walker, A.J., Bhaskaran, K. et al. OpenSAFELY: factors associated with COVID-19 death in 17 million patients. Nature (2020). https://doi.org/10.1038/s41586-020-2521-4

Pre-Prints

Factors associated with COVID-19-related hospital death in the linked electronic health records of 17 million adult NHS patients

May 2020. Our first paper analyses the pseudonymised health data of over 17.4 million UK adults to discover the key factors associated with death from COVID-19.

Inhaled corticosteroid use and risk COVID-19 related death among 966,461 patients with COPD or asthma: an OpenSAFELY analysis

June 2020. This paper describes the effect of inhaled steroid on COVID-19 outcomes using data from almost a million people with asthma and COPD. We observed a small harmful association, which is likely due to unmeasured confounding. Our findings do not support the theory that these drugs might be protective in COVID-19, and patients who use steroid inhalers should continue to do so.

Supplemental Research

Post-publications supplement to Williamson, E.J., Walker, A.J., Bhaskaran, K. et al. OpenSAFELY: factors associated with COVID-19 death in 17 million patients. Nature (2020). https://doi.org/10.1038/s41586-020-2521-4

August 2020. In the above paper, working on behalf of NHS England, we estimated associations between a wide range of individual-level factors including demographics and comorbidities, and risk of COVID-19 death, but we did not explore interactions between variables. It is plausible that associations may depend on age, and evaluating this would inform more accurate risk prediction. The purpose of this supplement is therefore to present associations between individual-level factors and COVID-19 death,stratified by age group.

Download the supplement here.