The NHFA was established in 2007 for hospitals in England and Wales to monitor and improve the quality of care of patients admitted to hospital with a diagnosis of heart failure, capturing information on their clinical presentation, characteristics, investigations, specialist input, management, and outcomes in the real world.6,7 Further details about NHFA is presented in Supplementary material online, Method section. For the purpose of this analysis, we included data relating to an admission with a diagnosis of heart failure from 1 January 2018 to 31 May 2020 from England. We dichotomized study participants on the basis of their date of index hospitalization: COVID-19 period (1 February–31 May 2020) and pre-COVID-19 period (1 February–31 May 2018 and 1 February–31 May 2019). Furthermore, we excluded hospitals that did not submit data consistently each month during this period. We only included the first admission for heart failure during the whole study period (a patient could potentially be hospitalized more than once). Records with missing data for sex and National Health Service (NHS) identification number were excluded.