The incidence value is the most important key figure for the question of how much the municipalities intervene in the freedom of their citizens to combat pandemics.
But the numbers of the district offices, the state office for health and the Robert Koch Institute regularly deviate from each other.
How can that be?
RKI, LGL and the health authorities report different incidence figures every day.
There are several reasons for these deviations - from the time of publication to the calculation method.
The State Office for Health is reacting and wants to publish its figures earlier in the future.
Munich
- Since last Tuesday restaurants, hotels and schools have been closed in the Berchtesgaden district.
With a seven-day incidence of 272, the district administrator pulled the emergency brake.
Since then, the citizens of the Alpine district have been following the daily figures with a fearful eye.
Is the situation easing or is it getting worse?
The daily statistics of the Robert Koch Institute (RKI) and the Bavarian State Office for Health (LGL) should actually provide an overview.
But there the numbers sometimes differ significantly from the calculations of the district office.
Extreme example from this week: While the Berchtesgadener Land district office reported an increasing incidence of 295.5 on Tuesday evening, the value for the LGL was 219. For the RKI, the value on Wednesday morning was only 169.9 - before it rose again in the morning 270 was updated.
A discrepancy of over 100, how can that be?
The district office speaks of "technical problems".
It is not the only case of this type in the past few weeks.
The district of Erding hung for days between the limit value of the red and green Corona traffic lights: According to figures from the local district office, it has long since fallen into the next traffic light level, and the LGL had to wait for updates.
In the Weilheim-Schongau district, too, after a transmission error at the LGL, a falling incidence was reported, although numerous new infections were reported.
One reason for the data salad in the corona incidence: the time of publication.
The data discrepancy has various causes.
The district offices are obliged to report corona cases to the LGL.
This is done electronically using the "Surfnet" software.
The LGL publishes the status from 8 a.m. to 2 p.m.
But: The evening before, current figures from the LGL are sent to the RKI, which in turn publishes the status from midnight.
All cases that arrive at the LGL after being reported to the RKI only appear in the LGL overview - but not in that of the RKI.
"We are always a bit more up-to-date than the RKI," says LGL director Walter Jonas.
The time at which the positive laboratory result appears at the health department is decisive for the LGL statistics.
Sometimes, however, a case is not passed on to the LGL on the same day - for example because the health authorities first track the contacts of the infected.
Such a case can end up in a later daily summary at the district office, but is then assigned to the actual reporting day at the LGL - this also shifts the incidence.
The LGL calls this process a "plausibility check", in which the information provided by the health authorities is checked and the incidence is calculated.
“A single case can decide whether a district breaks the threshold,” says Jonas.
The number of inhabitants used for the calculation can also ensure different incidences.
LGL and RKI use the official statistics as of December 31, 2019. If a district uses more recent population figures or rounds the value, the incidence changes.
And then there are the technical difficulties.
"We were not always able to identify the cause because neither the health authorities nor us were shown an error message," says Jonas.
In some cases, missing reports were not noticed until the next day.
The State Office for Health wants to get faster
Jonas emphasizes that his employees and the health authorities are working to the limit.
However, he sees room for improvement in the timing of the figures published by the LGL.
“We are currently checking whether we can publish the figures from 8 a.m. much earlier than at 2 p.m. in the future.
Because we see that it raises questions when we publish different figures almost simultaneously with the district offices. ”However, it is not possible to record the data in real time with the current software.
So when does the Bavarian corona traffic light apply unless a nationwide lockdown has just been announced?
The stricter rules automatically apply as soon as the district appears on the respective list (yellow, red, dark red) on the website of the Bavarian Ministry of Health.
This classification is based on the incidence number in the LGL.
A spokesman for the Ministry of Health emphasizes, however, that each district can also adopt its own measures if, according to its own calculations, a higher threshold has already been broken.
