Evolution of Coronavirus Disease 2019 (COVID-19) Symptoms During the First 12 Months After Illness Onset

BACKGROUND: Few robust longitudinal data on long-term coronavirus disease 2019 (COVID-19) symptoms are available. We evaluated symptom onset, severity and recovery across the full spectrum of disease severity, up to one year after illness onset. METHODS: The RECoVERED Study is a prospective cohort study based in Amsterdam, the Netherlands. Participants aged ≥18 years were enrolled following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis via the local public health service and from hospitals. Standardized symptom questionnaires were completed at enrollment, 1 week and month later, and monthly thereafter. Clinical severity was defined according to World Health Organization (WHO) criteria. Kaplan-Meier methods were used to compare time from illness onset to symptom recovery, by clinical severity. We examined determinants of time to recovery using multivariable Cox proportional hazards models. RESULTS: Between 11 May 2020 and 1 May 2021, 342 COVID-19 patients (192 [56%] male) were enrolled, of whom 99/342 (29%) had mild, 145/342 (42%) moderate, 56/342 (16%) severe, and 42/342 (12%) critical disease. The proportion of participants who reported at least 1 persistent symptom at 12 weeks after illness onset was greater in those with severe/critical disease (86.7% [95% confidence interval {CI} = 76.5–92.7%]) compared to those with mild or moderate disease (30.7% [95% CI = 21.1–40.9%] and 63.8% [95% CI = 54.8–71.5%], respectively). At 12 months after illness onset, two-fifths of participants (40.7% [95% CI = 34.2–7.1]) continued to report ≥1 symptom. Recovery was slower in female compared to male participants (adjusted hazard ratio [aHR] 0.65 [95% CI = .47–.92]) and those with a body mass index [BMI] ≥30kg/m(2) compared to BMI <25kg/m(2) (hazard ratio [HR] 0.62 [95% CI = .39–.97]). CONCLUSIONS: COVID-19 symptoms persisted for one year after illness onset, even in some individuals with mild disease. Female sex and obesity were the most important determinants of speed of recovery from symptoms.