Long-term physical capacity following COVID-19: A prospective, three-year study

Abstract

Objectives: COVID-19 impacts physical and respiratory health, and the clinical presentation ranges from asymptomatic cases to severe infections requiring hospitalisation. While the long-term effects on lung function and physical capacity are well-documented in moderate to severe cases, the long-term outcome for individuals with mild COVID-19 remains poorly understood. This study investigates the long-term recovery of physical capacity and breathlessness among both hospitalised and non-hospitalised individuals.

Methods: This prospective cohort study enrolled individuals with confirmed SARS-CoV-2 infection between April 2020 and May 2021 through the CoVUm-study. Participants underwent assessments of lung function at 3-6 months after infection and attended follow-ups up to three years post-infection. Physical capacity was evaluated at follow-ups, using the one-minute sit-to-stand test and the modified Medical Research Council scale to assess breathlessness.

Results: The cohort included 291 participants, 35% of whom were hospitalised during SARS-CoV-2 infection. At the 3-year follow-up, 191 participants completed the physical capacity test and 179 had an assessment of breathlessness. Physical capacity improved significantly in the total cohort up to two years post-infection, where improvement plateaued. Hospitalisation and impaired diffusing capacity were significantly associated with reduced physical capacity (beta -6.4, p < 0.001; beta -8.9, p < 0.001, respectively) and breathlessness (beta 3.9, p < 0.001; beta 1.6, p = 0.012, respectively). While non-hospitalised participants demonstrated improvements in physical capacity for up to two years, improvement for hospitalised individuals plateaued by six months.

Conclusion: Hospitalisation and impaired diffusing capacity are strong independent predictors of reduced physical capacity and persistent breathlessness up to three years post-infection. Non-hospitalised individuals also experience long-term reductions in physical capacity, underscoring the need for targeted rehabilitation strategies.

Keywords: Breathlessness; COVID-19; Diffusing capacity of the lung; Physical capacity.