Fig. 4
Positive and negative predictive values (PPV in 4a and NPV in 4b), for New York, depending on whether an early warning was issued or not. Higher color intensity corresponds to predictive values closer to the value of 1.
For Italy, the overall sensitivity for EVI was 0.82 (0.75; 0.89) and the specificity was 0.91 (0.88; 0.94). For New York, the corresponding values were 0.55 (0.47; 0.64) and 0.88 (0.84; 0.91).
Sensitivity analysis results for Italy, under alternative \(r\) specification (i.e., \(r=\frac{1}{1.5}\)), are in Figure 5. The overall sensitivity and specificity, for \(r=\frac{1}{1.5}\), were 0.75 (0.66; 0.85) and 0.93 (0.91; 0.96), respectively.