COVID-19-related mortality in a real-world cohort of 18 883 patients with premalignant and malignant haematological neoplasms: An analysis from the UK's Haematological Malignancy Research Network.

When the World Health Organization (WHO) declared the global COVID-19 pandemic, it was recognised that patients with haematological cancers would be more susceptible to severe disease. Set within a UK population of ~4 million (https://hmrn.org/), all patients diagnosed with haematological neoplasms 2005-2019 who were alive on 1 January 2020 were followed up until March 2023. For comparative purposes, a similar age- and sex-matched general population cohort was also constructed. COVID-19 deaths were classified using ICD-10 codes and a multiple cause of death analysis was undertaken using a competing risk approach. Deaths of 486/18 883 haematology patients were attributed to COVID-19, yielding a cumulative incidence of 2.59% (95% confidence interval [CI]: 2.37-2.82) that was significantly higher than that of the general population (1.65; 95% CI: 1.58-1.72). In both cohorts, risks were higher in men, older people and those with co-morbidities. Within the patient cohort, excess mortality was largely concentrated in those suffering from more indolent conditions. Patients with the premalignancy MBL suffered from the highest excess mortality in the early phase of the pandemic when, unlike patients with malignancies, they were not advised to shield. Effects of shielding were evident and a clear vaccination benefit was demonstrated, with the exception of CLL and MCL; findings that warrant consideration in relation to other viruses.