Clinical Outcomes and Risk Factors of Post-COVID Pulmonary Fibrosis in Hospitalized Patients

Abstract

Background: Post-COVID pulmonary fibrosis is an important long-term respiratory complication among patients recovering from moderate-to-severe COVID-19, particularly those requiring hospitalization. Persistent fibrotic changes may lead to chronic dyspnea, impaired pulmonary function, oxygen dependency, and reduced quality of life. Identification of high-risk patients is essential for timely follow-up and intervention. Objective: To evaluate the clinical outcomes and risk factors associated with post-COVID pulmonary fibrosis among hospitalized patients. Methodology: This retrospective observational study was conducted at the Department of Medicine, Liaquat University of Medical & Health Sciences, Jamshoro, from August 2024 to July 2025. A total of 212 adult patients previously hospitalized with RT-PCR-confirmed COVID-19 infection were included through consecutive non-probability sampling. Patients with follow-up high-resolution computed tomography chest performed at least 12 weeks after recovery were included. Patients with pre-existing interstitial lung disease, pulmonary fibrosis, active pulmonary tuberculosis, connective tissue disease-related lung involvement, lung malignancy, or incomplete records were excluded.  Data were analyzed using SPSS version 26.0. Results: Post-COVID pulmonary fibrosis was identified in 49 patients, giving a prevalence of 23.1%. Patients with fibrosis were significantly older than those without fibrosis (59.8 ± 12.6 vs 50.7 ± 13.2 years, p=0.0003). Smoking history, obesity, diabetes mellitus, prolonged hospital stay, ICU admission, oxygen requirement, mechanical ventilation, and raised inflammatory markers were significantly associated with fibrosis. Fibrotic patients also had higher rates of persistent dyspnea, chronic cough, oxygen dependency, pulmonary function abnormalities, and rehospitalization. Multivariable regression identified advanced age, smoking history, ICU admission, and mechanical ventilation as independent predictors. Conclusion: Post-COVID pulmonary fibrosis affected nearly one-quarter of hospitalized COVID-19 survivors and was associated with severe acute illness and poorer respiratory outcomes.