Modifications to the study protocol
RPE, dyspnea
COVID-19 PNEUMONIA, SECONDARY
Level of dyspnea, RPE after the 3MWT, and PH from VBG analysis were considered as secondary outcome measurements, while they were identified as primary outcomes in registration. History of intubation due to COVID-19 pneumonia was considered as another exclusion criteria. Also, the survival rate and HRQOL assessment were evaluated after three months as second follow-up. The permissions for these amendments were obtained from the ethical committee. The details and reason for the protocol modifications are presented in 