Almost a third of people report at least one ongoing symptom between 6 and 12 months after their coronavirus infection, a survey of 152,000 people in Denmark has found.
The study -that was published as a pre-print and has not yet been peer-reviewed- includes one of the largest groups yet of people who were not hospitalized with COVID, and followed them for longer than other major studies, the researchers from Denmark's State Serum Institute (SSI) said.
The questionnaire-based study suggested that the most commonly reported long-term symptoms were changes in sense of smell and taste, as well as fatigue.
Conducted between September 2020 and April 2021, well before the recent Omicron variant surge, the survey compared the responses of 61,002 people who had tested positive for the coronavirus six, nine, or 12 months before with those of 91,878 people who had tested negative.
In total, 29.6% of the respondents who had tested positive reported at least one ongoing physical symptom 6 to 12 months after infection, compared to 13% in the control group.
Just over half (53.1%) of those with positive tests said they had experienced either mental or physical exhaustion, sleep problems, or cognitive problems within the 6 to 12 months after infection. That compared to 11.5% in the control group.
New diagnoses of anxiety and depression were also more common among those with a history of SARS-CoV-2 infection, the study showed.