Combined poor outcome was defined as a composite of in-hospital mortality, ICU length of stay ≥ 7d, invasive mechanical ventilation ≥ 7d and ECMO. IAPA = influenza-associated pulmonary aspergillosis, non-IAPA = influenza patients without IAPA, IQR = interquartile range, ICU = intensive-care unit, ECMO = extracorporeal membrane oxygenation, ARDS = acute respiratory distress syndrome according Berlin criteria^{18, 19}