Covid-19 growth rate analysis: application of a low-complexity tool for understanding and comparing epidemic curves.

Introduction: The acceleration of new cases is important for the characterization and comparison of epidemic curves. The objective of this study was to quantify the acceleration of daily confirmed cases and death curves using the polynomial interpolation method.

Methods: Covid-19 epidemic curves from Brazil, Germany, the United States, and Russia were obtained. We calculated the instantaneous acceleration of the curve using the first derivative of the representative polynomial.

Results: The acceleration for all curves was obtained.

Conclusions: Incorporating acceleration into an analysis of the Covid-19 time series may enable a better understanding of the epidemiological situation.