Which early indicator allows for a better understanding of the evolution of the COVID-19 epidemic in France?

We provide an explanation for the apparent discrepancy between the dynamic of the positive COVID-19 test rates and of the numbers of COVID-19-related hospital and intensive care admissions and deaths in France. We highlight the existence of a latency period of around 5 weeks between the infections of young individual (generally asymptomatic) to older individuals that may have a severe form of the disease and may be hospitalized. If the overall positive detection rate provided relevant information until the end of August, since the beginning of September the overall positive detection rate has reached a plateau and no longer provides relevant information on the current state of the epidemic. We show that the positive detection rate in the 70+ age group is a relevant and early indicator of the epidemic. Furthermore, we have shown an identical doubling time of around 16 days for the following indicators: the positive tests rate for the 70+ age group, the number of new admissions to hospital, intensive care unit admissions and deaths.