Provided to YouTube by Universal Music Group27 · Fall Out BoyFolie à Deux℗ 2008 The Island Def Jam Music GroupReleased on: 2008-01-01Producer, Studio Person...

The study cohort is based on the EFTER-COVID survey, which was established in order to study the degree of, nature of and duration of possible post-acute symptoms and health problems among SARS-CoV-2 test-positive individuals using test-negative as a reference group27. Test-positive and test-negative individuals were invited to participate using information on SARS-CoV-2 PCR test results from the national COVID-19 surveillance system at the Statens Serum Institut28,29. Since 1968, the Danish Civil Registration System has assigned a unique personal ID-number (the CPR-number) to every person resident in Denmark30, which is used as a personal identifier in all Danish national registers including the COVID-19 surveillance system. Invitations to participate in EFTER-COVID were sent to test-positive and test-negative individuals using E-Boks, a national digital secure two-way communication system between citizens and authorities in Denmark, via the CPR-number31. E-Boks usage is mandatory for all inhabitants in Denmark aged 15 years or older, unless exempted (in 2022 used by 92% of the relevant age group)27. In general, all individuals who received a positive PCR-test result for the first time were invited. Test-negative individuals with no prior positive test result were density matched on test-date with a test-negative/test-positive individual ratio of 3:2 in anticipation of a...

Provided to YouTube by Universal Music Group27 · Fall Out BoyFolie à Deux℗ 2008 The Island Def Jam Music GroupReleased on: 2008-01-01Producer, Studio Person...