Figure 3.

Epidemiologic curve of severity and death in middle-aged and older patients.

(a) and (b) show the number of patients in each category in the middle and old age groups, respectively. The upward graphs (discharged/transferred) show the patients who were alive at the time of discharge, and the downward graphs (deaths) show the patients who died during hospitalisation. “Transferred” included patients who were transferred to either different hospital, non-medical facility, or long-term care facility. The outcome of patients who were transferred from the hospitals participating in the study at the time of admission are summarised in Supplementary Table 3. Detailed numbers in the figure are presented in Supplementary Table 2.

No oxygen: patients who were never supported with supplemental oxygen during hospitalisation.

Oxygen: patients who were supported with non-IMV or supplemental oxygen (including high-flow oxygen devices) during hospitalisation.

IMV/ECMO: Patients who were supported with invasive mechanical ventilation (IMV) or extracorporeal membrane oxygenation (ECMO).