Admission to hospital, admission to ICU, and overall survival upon COVID-19 in CLL. Kaplan-Meier curves for (A) admission to hospital, (B) admission to ICU, (C) overall survival (OS) for the EHR cohort, (D) OS for the population cohort, and (E) OS for the combined cohort. Data are stratified for the following time periods: period 1: 12 March and 16 September 2020 for EHR and population cohorts, respectively, to December 2020; period 2: January 2021 to 25 November 2021; period 3: 26 November 2021 to December 2021; and period 4: 1 January 2022 to 28 January 2022 and 7 March 2022 for EHR and population cohorts, respectively. Patients represented within the EHR cohort (A-C) are excluded from the population cohort (D). P values were calculated using log-rank test for differences across the 4 subgroups.