COVID-19(37) Patient(28) SARS-CoV-2(21) outcome(18) Analysis(15) age(13) Infection(13) Treatment(13) death(11) SARS-COV-2 infection(11) Mortality(11) the SARS-CoV-2(10) severe COVID-19(9) treated(9) significantly(9) Multiple myeloma(9) disease(9) Retrospective study(8) median age(8) died(8) therapy(8) Cohort(8) Factor(7) Prognosis(7) median(7) antibody(7) was performed(7) leukemia(7) Hospitalization(6) Varicella zoster virus.(6)