A Simple Mathematical Model for Estimating the Inflection Points of COVID-19 Outbreaks

Zhanshan (Sam) Ma

The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10. 1101 Listed in Table 1 included the PLEC parameters (w, d, c) and the p-values [w(p), d(p), c(p)] from estimating the corresponding parameters. These p-values measure the significance levels for estimating these parameters: a p-value<0.05 indicating that the goodness-of-fitting to the model is statistically satisfactory from the perspective of the particular parameter. R 2 (R-squared) is of limited reference value for non-linear fitting problem, but it also confirmed the goodness-offitting as illustrated by the p-values for individual parameters. Obviously, the most important items in Table 1 are the I max and corresponding T max , the maximal infection number (eqn. 3) and the corresponding inflection time point (eqn. 4), respectively. Table 1 shows that PLEC fitted to virtually all datasets satisfactorily in terms of the p-values except for a few negligible parameter cases (p-value>0.05 in 4 out of 52). It should be noted that the 4 parameter cases that failed to pass significance tests only means that the parameter values may have too high standard error (variability) and the failure does not necessarily mean that the model structure failed. Therefore, the model could still be used for estimating T max and I max , as long as the tests with actual observations are satisfactory, as explained below. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.