Model of Socially-Weighted Prevalence
Although we do not usually deal with epidemiology in the field of „Mathematics for Vehicle Development“, we have a lot of statistical expertise in dealing with incomplete data sets („missing data“) and non-representative samples. With the help of these statistical tools we have developed (led by Jochen Fiedler) the model of socially-weighted prevalence, which determines the number of unreported cases from the following considerations:
- The virus has spread to all age groups. In younger age segments it should have spread more strongly due to higher mobility and number of contacts.
- In detailed data sets with reported infections, this uniform mixing is not apparent. The virus seems to have spread more in the higher age segments.
- This is due to the way testing is carried out in the countries. For example, in some countries only people with serious symptoms are tested, sometimes because capacities do not allow for more. These are mostly older people.
- This allows us to draw conclusions about the number of unreported cases, especially in younger age segments.
Based on the data of April 2nd 2020, our model has determined that there must be at least 22,107 undetected infections in Germany in addition to the 73,268 reported infections. For Italy, 476,297 undiscovered infections are obtained (in addition to the 105,630 reported).
These estimated numbers of undetected infections alone reduce the difference of the case mortality rates to a factor 2 (instead of over 10).
In the following, we explain our approach in more detail: