Prevalence of long COVID in a national cohort: longitudinal measures from disease onset until 8 months' follow-up

Abstract

Objectives: Persistence of COVID-19 symptoms in nonhospitalized individuals beyond a few months has not been well characterized. In this longitudinal study from the Faroe Islands, we present prevalence of long COVID in mainly nonhospitalized patients who were followed up for up to 8 months.

Methods: All Faroese individuals with confirmed COVID-19 diagnosis from August to December 2020 were invited to participate in this study (n = 297). Demographic and clinical characteristics and self-reported symptoms were ascertained prospectively using a detailed questionnaire administered at repeated phone interviews.

Results: A total of 226 individuals participated at baseline (226/297, 76% participation rate), of whom 170 participants had more than 3 months follow-up. Of these, 39% (n = 67/170, 95% confidence interval [CI] 32-37%) reported persistent symptoms (median [range] 168 [93-231] days) after the acute phase and 8% (n = 14/170, 95% CI 5-13%) reported severe persistent symptoms. The most prevalent symptoms were fatigue (17%) and smell (17%) and taste (14%) dysfunction. Long COVID was more common in people reporting daily medication use (odds ratio 2.34, 95% CI 1.02-5.37).

Conclusion: Our results show that symptoms may take months to resolve, even among nonhospitalized individuals, with a mild illness in the acute phase. Continued monitoring for long COVID is needed to evaluate the added risk of a potential public health concern.

Keywords: COVID-19; Faroe Islands; Long COVID; Longitudinal study; Persisting symptoms.

Figure 1

Prevalence (%) of long COVID (>3 months after COVID-19) (black bar, n = 170) and symptoms during the acute phase (gray bars, n = 226) in Faroese patients with PCR-confirmed COVID-19 from August to December 2020. COVID-19, coronavirus disease 2019; PCR, polymerase chain reaction.