Participants
ADVERSE EVENTS, COVID-19 PNEUMONIA
All participants were patients with COVID-19 pneumonia at a severe stage [Participants who met one of the following conditions were withdrawn/dropped out from the study: 1) Unable to complete at least three sessions due to intubation, medical instability situation, or die; 2) Dissatisfaction to continue to the study for any reason; and 4) Occurring unpredictable adverse events during applying interventions.