A Systematic Review of Persistent Symptoms and Residual Abnormal Functioning following Acute COVID-19: Ongoing Symptomatic Phase vs. Post-COVID-19 Syndrome

This systematic review compared ongoing symptomatic COVID-19 (OSC) and post-COVID-19 syndrome (PCS) by analyzing 39 studies with sample sizes ranging from 32 to 1733. Fatigue was the most common symptom in both phases, affecting 43% during OSC and 44% during PCS. Other prevalent symptoms included sleep disorders, dyspnoea, and cough. Abnormal lung function and imaging were more common in OSC, while anxiety, depression, and decreased quality of life were more frequent in PCS. The evidence quality was moderate, indicating a need for further research to understand long-term symptom trajectories in long COVID.