Kaplan–Meier estimate of survival for entire MPN patient cohort covering time from COVID-19 diagnosis censored at date of data submission (A). Effect of age (B), COVID-19 severity on admission according to WHO criteria (C), and MPN subtype (D). Effect of age by MPN subtype, each box represents a patient, solid fill box denotes survival and hatched box death (E). Effect of ruxolitinib treatment in patients aged over 75 years (F). ET essential thrombocythemia, PV polycythemia vera, MF myelofibrosis (including primary and secondary), O other MPN (including MDS/MPN overlap and MPN unclassifiable).