Policymakers need a clear and fast assessment of the real spread of the epidemic of
COVID-19 in each of their respective countries. Standard measures of the situation
provided by the governments include reported positive cases and total deaths. While
total deaths immediately indicate that countries like Italy and Spain have the worst
situation as of mid April 2020, on its own, reported cases do not provide a correct
picture of the situation. The reason is that different countries diagnose diversely and
present very distinctive reported case fatality rate (CFR). The same levels of reported
incidence and mortality might hide a very different underlying picture. Here we present
a straightforward and robust estimation of the diagnostic rate in each European country.
From that estimation we obtain an uniform unbiased incidence of the epidemic. The
method to obtain the diagnostic rate is transparent and empiric. The key assumption of
the method is that the real CFR in Europe of COVID-19 is not strongly
country-dependent. We show that this number is not expected to be biased due to
demography nor the way total deaths are reported. The estimation protocol has a
dynamic nature, and it has been giving converging numbers for diagnostic rates in all
European countries as of mid April 2020. From this diagnostic rate, policy makers can
obtain an Effective Potential Growth (EPG) updated everyday providing an unbiased
assessment of the countries with more potential to have an uncontrolled situation. The
method developed will be used to track possible improvements on the diagnostic rate in
European countries as the epidemic evolves.
