Development of long-covid, or prevalent complaints in general?

Abstract Objectives: To study the prevalence and patterns of typical post-covid complaints in ~2.3 million persons with and without confirmed COVID-19.Methods: In a Nation-wide population-based prospective cohort study, we studied all persons aged 18-70 years living in Norway and who tested positive (n=75 979), negative (n=1 167 582) and who were not tested for SARS-CoV-2 (n=1 084 578) from August 1st 2020 to August 1st 2021 (non-hospitalized from -2 to +14 days from test date), who were, or were not vaccinated against COVID-19. Our main outcome measures were the period prevalence of single-occurring or different combinations of complaints based on medical records: 1) Pulmonary (dyspnea and/or cough), 2) Neurological (concentration problems, memory loss), and/or 3) General complaints (fatigue). Results: In persons testing positive, 64 (95% confidence interval: 54 to 73) and 122 (111 to 113) more persons per 10 000 persons had pulmonary complaints 5-6 months after the test compared to 10 000 persons testing negative or untested, respectively. The corresponding difference in prevalence of general complaints (fatigue) was 181 (168 to 195) and 224 (211 to 238) per 10 000, and of neurological complaints 5 (2 to 8) and 9 (6-13) per 10 000. Overlap between complaints was rare.Conclusions: Post-covid complaints were only slightly more prevalent in persons with than without confirmed COVID-19. Still, long-covid may pose a substantial burden to healthcare systems in the future given the lasting high incidence of symptomatic COVID-19 in both vaccinated and unvaccinated individuals.