LAUSR

We discuss the statistical method used in Italy to estimate the reproduction number Rt at the regional level. In Italy, Rt is not only used to provide a picture of the epidemic spread, but rather as a decision tool to plan and organize non-pharmaceutical interventions by imposing a-priori thresholds to define different levels of risks. We comment on methodological limitations of the statistical approach which lead to a misuse of Rt. Though remarking the importance of the reproduction number to evaluate the severity of the COVID-19 spread, we must be cautious to use Rt over its real meaning, and avoid its use to impose constraints to the dailylife activities as these would be based on an unreliable estimate of the reproduction number. This article is protected by copyright. All rights reserved.