Fig. 1

 Sex distribution by age and hospitalization length of COVID-19 patients during the two waves A Total percentage and number (in the bars) of hospitalized females (dark gray) and males (light gray) divided according to the indicated age groups (top left panel) and age groups and waves (bottom left panel); 45–59 and 60–74 age groups, females vs males: chi-square = 24.72, P = 0.000 (top left panel), and 45–59 and 60–74 age groups, females vs males: chi-square = 4.403, P = 0.036 (bottom left panel). B Number of days between symptom onset and hospital admission in patient’s groups divided by age (top right panel-ANOVA: main effect sex F = 0.007, P = 0.933, main effect age F = 2.338, P = 0.07, interaction age × sex F = 1.364, P = 0.253) and by age and waves (bottom right panel-ANOVA: main effect sex F = 2.504, P = 0.807; main effect age F = 2.089, P = 0.100; main effect wave F = 14.395, P = 0.000; age × wave F = 1.664, P = 0.173; age × sex F = 1.937, P = 0.122; sex × wave F = 0.238, P = 0.626; sex × age × wave F = 1.390, P = 0.235)