Comparison of Google Flu Trends to Actual Flu Activity and Robustified GFT for 2009 Weeks 35 to 37

2009 Week 36 Nowcasts

Current CDC report (Week 35) Google Flu Trends (Week 35)
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Improved Google Flu Trends (Week 36) Google Flu Trends (Week 36)
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Improved Google Flu Trends (Week 37) Current Google Flu Trends (Week 37)
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Color coding is based on region-specific baselines:
green: below 0.5 baseline;
light green: between 0.5 baseline and 0.75 baseline;
yellow: between 0.75 baseline and baseline;
orange: between baseline and 1.5 times baseline;
red: between 1.5 baseline and 3 times baseline;
dark red: between 3 and 6 times baseline;
very dark red: 6 times baseline and higher.

The CDC uses the 10 HHS regions in its reports. Google Flu Trends reports activity by state. This was aggregated to HHS regions using the 2008 population estimates from the US Census (so aggregation takes variations in population density into account).

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