Study setting
This trial was conducted at the Department of Otorhinolaryngology, Head and Neck Surgery of the Faculty of Medicine of the University of Cologne, Germany. Outpatients visiting Corona test centres were informed about the possibility of participating in the trial. Patients aged 18 to 60 years were eligible to participate if tested positive for SARS-CoV-2 in a Corona test centre by PCR test within 48 h prior to inclusion and had to quarantine at home due to instructions of the local health authority. A complete list of inclusion and exclusion criteria is presented in Table Inclusion and exclusion criteria for study participation.