Symptoms persisting after hospitalization for COVID-19: 12 months interim results of the CO-FLOW study

After COVID-19 long-term sequelae are frequently reported. We aimed to longitudinally assess persistence and clusters of symptoms up to 12 months after hospitalization for COVID-19, and to assess determinants of the main persistent symptoms. In this multicenter prospective cohort study patients with COVID-19 are followed up at 3, 6, and 12 months after hospital discharge; we present interim results for persistent symptoms up to 12 months. Symptoms were clustered into physical, respiratory, cognitive, and fatigue symptoms. Of the 492 patients included, 97%, 95.5%, and 92.5% had at least 1 persisting symptom at 3, 6, and 12 months after discharge, respectively (p=0.010). Muscle weakness, exertional dyspnea, fatigue, and memory and concentration problems were the most prevalent symptoms at follow-up (>50%). Over time, muscle weakness, hair loss, and exertional dyspnea decreased significantly (p<0.001). Only the physical (p=0.025) and respiratory (p<0.001) symptom cluster declined significantly over time. Female gender was the most important predictor of persistent symptoms and co-occurrence of symptoms from all clusters. Shorter hospital stay and treatment with steroids were related to decreased muscle weakness; comorbidity and being employed were related to increased fatigue; and shorter hospital stay and comorbidity were related to memory problems. The majority of patients experienced COVID-19 sequelae up to 12 months after hospitalization. Only the physical and respiratory symptoms showed slow gradual decline. This finding stresses the importance of finding the underlying causes and effective treatments for post-COVID condition, beside adequate COVID-19 prevention.