Figure 1.
Weekly percentage of sentinel physician visits related to influenza-like illness (ILI) reported by the Centers for Disease Control and Prevention (CDC) and estimated using Google Flu Trends (GFT), United States, October 2010–March 2014.
The final CDC value (f%ILINet; blue) is compared to the GFT estimate (%GFT; red) and the transformed GFT estimate using c = 0.65 (transformed %GFT; turquoise). The GFT model was recalibrated during the 2013–14 season: dashed lines show the period in which GFT estimates were retrospectively re-estimated using the 2013 GFT model.
Table 1.
Comparing estimates of the weekly percentage of physician visits related to influenza-like illness (ILI) based on Google Flu Trends (GFT) to values reported by the Centers for Disease Control and Prevention (CDC), United States, October 2010–March 2014.