**7. Prognosis in Patients with COVID-19-Associated Lung Fibrosis**

COVID-19 survivors were shown to have significant functional and radiological abnormalities after 4 months, which were attributed to small-airways and lung parenchymal disease [63]. Radiological abnormalities were associated with more severe or critical diseases [63]. Another study with a 6-month follow-up showed fibrotic changes in more than one-third (40 of the 114 patients, 38%) of survivors after severe COVID-19 pneumonia [28].

A recent meta-analysis including 70 studies with a median follow-up of 3 months, showed fibrotic changes in one-third of patients, whereas no significant resolution was observed in fibrotic changes [64]. Others have observed radiological evidence of lung injuries suggestive of lung fibrosis, but with a reversible component, thus not being the classical fibrotic changes known to us previously in other fibrotic lung diseases. It is, therefore, difficult to differentiate reversible lung injuries from irreversible pulmonary fibrosis, raising the question under what circumstances and criteria antifibrotic therapy is truly indicated [14].
