Two- and 3-year outcomes in convalescent individuals with COVID-19: A prospective cohort study

Abstract

As the long-term consequences of coronavirus disease 2019 (COVID-19) have not been defined, it is necessary to explore persistent symptoms, long-term respiratory impairment, and impact on quality of life over time in COVID-19 survivors. In this prospective cohort study, convalescent individuals diagnosed with COVID-19 were followed-up 2 and 3 years after discharge from hospital. Participants completed an in-person interview to assess persistent symptoms and underwent blood tests, pulmonary function tests, chest high-resolution computed tomography, and the 6-min walking test. There were 762 patients at the 2-year follow-up and 613 patients at the 3-year follow-up. The mean age was 60 years and 415 (54.5%) were men. At 3 years, 39.80% of the participants had at least one symptom; most frequently, fatigue, difficulty sleeping, joint pain, shortness of breath, muscle aches, and cough. The participants experienced different degrees of pulmonary function impairment, with decreased carbon monoxide diffusion capacity being the main feature; results remained relatively stable over the 2-3 years. Multiple logistic regression analysis demonstrated that female sex and smoking were independently associated with impaired diffusion capacity. A subgroup analysis based on disease severity was performed, indicating that there was no difference in other parameters of lung function except forced vital capacity at 3-year follow-up. Persistent radiographic abnormalities, most commonly fibrotic-like changes, were observed at both timepoints. At 3 years, patients had a significantly improved Mental Component Score compared with that at 2 years, with a lower percentage with anxiety. Our study indicated that symptoms and pulmonary abnormalities persisted in COVID-19 survivors at 3 years. Further studies are warranted to explore the long-term effects of COVID-19 and develop appropriate rehabilitation strategies.

Keywords: COVID‐19; complications; long COVID; long‐term outcomes.