Fig. 9.

Comparison of curves for Calabria region. Left: y–axis on normal scale, right: on logarithmic scale. Regression line shown for $log(\mathrm{daily}\mathrm{confirmed})-log(\mathrm{daily}\mathrm{tested})\sim time$ with $95\%$ prediction band. Slope of regression with $95\%$ confidence interval: $a_{\mathrm{f}}=-0.074(-0.085,-0.063)$,this corresponds to a half-life (in days) of 9.315(8.122, 10.918). The slope of the regression $log(\mathrm{daily}\mathrm{confirmed})\sim time$ is $a_{\mathrm{raw}}=-0.052(-0.064,-0.040)$ corresponding to a half-life (in days) of 13.249(10.747, 17.271). The slope of the regression $log(\mathrm{daily}\mathrm{tests})\sim time$ is 0.022(0.016, 0.043) corresponding to a doubling time (in days) of 31.709(16.233, 42.761). Ratio of slopes for $a_{\mathrm{f}}/a_{\mathrm{raw}}=1.422$, with corresponding half-lives’ ratio: 0.703. The slope of the regression $log(\mathrm{cumulative}\mathrm{confirmed})-log(\mathrm{cumulative}\mathrm{tested})\sim time$ is $-0.023(-0.024,-0.022)$ corresponding to a half-life (in days) of 30.582(29.262, 32.028)