Fig. 20.

Comparison of curves for Piemonte 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: $a_{\mathrm{f}}=-0.048(-0.052,-0.043)$, this corresponds to a half-life (in days) of 14.451(13.207, 15.954). The slope of the regression $log(\mathrm{daily}\mathrm{confirmed})\sim time$ is $a_{\mathrm{raw}}=-0.013(-0.019,-0.006)$ corresponding to a half-life (in days) of 53.716(35.637, 109.020). The slope of the regression $log(\mathrm{daily}\mathrm{tests})\sim time$ is 0.035(0.030, 0.052) corresponding to a doubling time (in days) of 19.769(13.415, 23.179). Ratio of slopes for $a_{\mathrm{f}}/a_{\mathrm{raw}}=3.717$, with corresponding half-lives’ ratio: 0.269. The slope of the regression $log(\mathrm{cumulative}\mathrm{confirmed})-log(\mathrm{cumulative}\mathrm{tested})\sim time$ is $-0.018(-0.019,-0.016)$ corresponding to a half-life (in days) of 39.243(35.548, 43.796)