Figure 3.

Age dependence in the natural history of coronavirus disease 2019 (COVID-19) infection (n=677). Age-dependent variation was examined with respect to (A) symptomatic illness, (B) risk of severe disease and (C) risk of death among infected individuals. Black diamonds show sample estimates plotted at the mid-point age of each age group (except for cases aged 0–19 years and for those aged ≥80 years, which were plotted at 15 and 85 years, respectively). Whiskers indicate the boundaries of the 95% confidence intervals, which were derived from Agresti's score interval. Solid curve lines show the risk of death based on univariate logistic regression taking age as a continuous explanatory variable. Dashed lines show the upper and lower 95% confidence intervals of the risks and were derived from the bootstrap method.