The National COVID-19 Prevalence Study
By participating in the study, you help the health authorities to understand the scope of the infection - and you may also learn if you yourself have been infected.
Excerpt of the letter received by 18,000 citizens inviting them to participate in the prevalence study
It is on everybody’s lips. The National COVID-19 Prevalence Study. But what is the study about? How is it conducted? And why does the study matter?
What is the objective of the prevalence study?
The objective of the study is to monitor how the COVID-19 epidemic is spreading in the population.
Who initiated the prevalence study?
The study was initiated in response to a political decision. The study formed part of the political agreement about the first phase of re-opening the country, decided back in April. It is conducted by Statens Serum Institut (SSI) in the context of Testcenter Denmark (TCDK).
How is the study organised?
The prevalence study has two parts:
In one part, periodic measurements are made of the level of COVID-19 virus antibodies by collecting a blood sample from the study participants. This provides information about how many people in the population have already had COVID-19. The study also includes a questionnaire that provides information about the symptoms experienced by those who have antibodies.
In the second part, investigators make a weekly assessment on the basis of PCR test results. Then, investigators can see if the number of COVID-19-positives in a region exceeds a pre-established threshold and whether additional measures may be needed.
How is the study conducted?
The study is conducted by drawing a number of citizens from the civil registration register (CPR) at random. These citizens receive an invitation letter through their e-Boks, inviting them to participate.
You participate by filling in a questionnaire and scheduling a test at the nearest community-track test centre (TCDK’s test centres).
What is the status on the study right now?
The study was initiated as early as week 19. Back then, citizens who lived close to one of the original test centres were invited to participate.
More recently, in weeks 34-36, a total of 18,000 citizens have been invited for PCR as well as antibody testing - these citizens represent a broad cross-section of the population.
“In this manner, we hope to achieve an update on how much the COVID-19 epidemic has advanced in the Danish population,” notes Head of Section Steen Ethelberg from the SSI. He adds:
“For the prevalence study to be useful, it is important that a sufficiently large amount of data is collected and that the study is representative.”
Why is it important to participate in the study?
The SSI therefore encourages everyone to support the prevalence study.
“By participating in the study, you help the health authorities understand the scope of transmission. At the same time, you receive information on whether it is likely that you have already had the infection yourself,” notes Steen Ethelberg.
For more information about the prevalence study, please see EPI-NEWS 37/2020