Emergency Department Visit Data for Rapid Detection and Monitoring of Norovirus Activity, United States
Figure 3. . . Correlation between the proportion of BioSense emergency department (ED) visits mapped by chief complaint to diarrhea subsyndrome and norovirus outbreaks as a function of total BioSense ED visits per month using state-specific data for the 6 states analyzed, United States, January 2007–April 2010. Correlation coefficients for each state are plotted by corresponding total ED visits/month on a logarithmic scale. Models tended to perform better in states with greater total ED visits. Higher correlation (R>0.60) was observed for states with >5,000 BioSense ED visits/month. State number labels on data points correspond to those in Table 2.