Laboratory confirmed hospitalized cases.

A The smoothed risk ratio of laboratory confirmed hospitalized cases in a single year age group compared to the overall risk in all age groups. Smoothed curves for each location were created by a locally weighted polynomial regression with fixed bandwidth of 4. B The smoothed weighted risk ratio (WRR) of laboratory confirmed hospitalized cases in a single year compared to the risk in all age groups combined using a fixed bandwidth of 4. The single year of age WRR used to create the smoothed curve are plotted as open circles and the 95% confidence bounds are shaded. The inset figure shows the truncated WRR from 0 to 29 years of age while the larger figure focuses on the ages from 30–100. C SiZer plot of the first derivative of the WRR by age. The X axis represents age while the Y axis corresponds to the log of the bandwidth (h). For example, log(0.6) corresponds to the fixed bandwidth of 4 used to create Figures A and B and a black horizontal line identifies this bandwidth. The shading corresponds to the significance and direction of the slope (first derivative) of the WRR by age: red is significantly decreasing, purple is possibly zero, blue is significantly increasing, and light grey represents areas where there is insufficient data to generate a smoothed curve. The grid lines correspond to 1 year of age intervals. D SiZer plot of the second derivative of the WRR by age, where the shading corresponds to that described for Figure 1C.

A 单一年龄组实验室确诊住院病例的平滑风险比（smoothed risk ratio），与全年龄组总体风险的比值。各地点的平滑曲线通过固定带宽为4的局部加权多项式回归生成。
B 单一年龄组实验室确诊住院病例的平滑加权风险比（WRR），以固定带宽4计算得到，与全年龄组合并风险的比值。用于生成平滑曲线的单年龄组加权风险比以空心圆点绘制，同时以阴影区域标示95%置信界。内嵌子图展示了0至29岁年龄段的截断加权风险比，主图则聚焦于30至100岁的年龄段。
C 按年龄划分的加权风险比一阶导数的SiZer图（SiZer plot）。横轴代表年龄，纵轴对应带宽的对数值。例如，log(0.6)对应生成图A与图B时使用的固定带宽4，图中以黑色水平线标示该带宽。阴影区域代表按年龄划分的加权风险比斜率（一阶导数）的显著性与方向：红色表示斜率显著下降，紫色表示斜率可能为零，蓝色表示斜率显著上升，浅灰色代表数据不足无法生成平滑曲线的区域。网格线对应1年的年龄间隔。
D 按年龄划分的加权风险比二阶导数的SiZer图，其阴影区域的含义与图1C一致。