1. Date of deaths’ occurence, registration, publication
The publication of a death by health monitoring agencies is not immediate. Four stages can be described, with each death having four possible dates: (i) the date of occurrence, (ii) the date of notification to the civil registry, (iii) the date of notification to the health agencies, and (iv) the date of publication. For example, in France, the legal deadline for declaring a death (step ii.) is 24 hours after its occurrence. In many countries, notification to health agencies is done in two stages. In the first stage, the death is notified to a regional agency, which in turn notifies a national agency.
Electronic platform systems are used to speed up the publication, for example in some hospitals; but these systems are not always generalised to all structures in the same country and do not always cover deaths in social and health institutions or at home.
It should therefore be remembered that the cumulative total of deaths reported daily by the countries only partially corresponds to the cumulative total of deaths that have occurred to date. In fact, "new announced deaths" do not represent all deaths in the last 24 hours, due to the process of transmitting the information, nor only deaths in the last 24 hours: new announced deaths include (1) the part of the day’s deaths that are already reported in the information system; (2) deaths that occurred in previous days, which have been progressively reported in the information system. Some countries, such as Denmark or the Netherlands, provide a daily correction of the previous daily totals, re-assining late reported deaths (see data provided for these two countries).
In Denmark it seems that an average of between twenty and thirty deaths are added to the daily total after a fortnight: the cumulative total of deaths on April 3rd was initially 139 deaths, and reached 170 deaths on April 21st , i.e. an additional 31 deaths were reassigned to April 3rd each following day (Figure 1.1).
While this update is important when looking at the daily dynamics of deaths in the different phases of the epidemic, it will probably not be possible to correct this information in a systematic way for all countries until the end of the epidemic. At this stage, the dynamics are approximations; the margin for correction depends on the delays in the registration and publication of deaths at the national level by health agencies.
Deaths publication in France
COVID-19: How are deaths counted in France?
("The conversation" Pison, Meslé)
Figure 1.1 Progressive update of daily total deaths counts with the progressive reassigned of deaths by COVID-19 (Denmark April 21st)
"Data and metadata" - Source : Statens Serum Institut