Abstract

Since the beginning of the pandemic, the world has registered more than 250 million confirmed cases and more than 5 million deaths. A web-based interactive dashboard with real-time hosted data was developed by the John Hopkins University Center for Systems Science and Engineering (CSSE) to provide researchers, public health officials and the general public with an easy to use tool to visualize and track the pandemic as it unfolds around the world. The incidence rate is a measure of events that represents the transition between two states, not from disease to disease, so it is an estimate of risk. When looking at the aforementioned incidence rate that is reported for Angola and other countries, we note that the observation period in which the incidence rate is calculated and presented in the Panel is missing or not clearly defined, although the choice of this element is entirely arbitrary, but must be clearly defined in the calculation. The panel considers as new cases all cases from notification of the first confirmed case (March 21, 2020 in the Angola example) to the review date (Nov. 30, 2021). In our view, it is completely irrelevant to estimate the risk of a potentially epidemic disease over long observation periods, as presented in the panel when the objective is to allow decision making to control and assess the pandemic by public health authorities. We think that it would be entirely sensible and convenient to present this indicator in short observation periods of a maximum of 28 days and a minimum of 7 days.

Keywords: Incidence rate; Covid-19; John Hopkins University Interactive Dashboard