Br J Haematol. 2021 May 24. doi: 10.1111/bjh.17522. Online ahead of print.
Infection with coronavirus disease-2019 (COVID-19) may predispose for venous thromboembolism (VTE). There is wide variation in reported incidence rates of VTE in COVID-19, ranging from 3% to 85%. Therefore, the true incidence of thrombotic complications in COVID-19 is uncertain. Here we present data on the incidence of VTE in both hospitalised and non-hospitalised patients from two ongoing prospective cohort studies. The incidence of VTE after diagnosis of COVID-19 was 3·9% [95% confidence interval (CI): 2·1-7·2] during hospitalisation, 0·9% (95% CI: 0·2-3·1) in the three months after discharge and 0·2% (95% CI: 0·00-1·25) in non-hospitalised patients, suggesting an incidence rate at the lower end of that in previous reports.