Fig. 3
From: Detecting signals of seasonal influenza severity through age dynamics
Retrospective and early warning severity indexes compared to the benchmark. a Retrospective severity (\(\overline {\rho _{s, r}}\)) has a positive relationship with the benchmark (R= 0.71, p-value = 0.05). b Early warning severity (\(\overline {\rho _{s, w}}\)) has a positive relationship with the benchmark (R= 0.59, p-value = 0.16). The 2003–04 season was removed because it was an early flu season and the early warning period occurred after the retrospective period. Point color corresponds to qualitatively-assigned severity category, where red is severe, yellow is moderate, and blue is mild