tetano
Editor, Senior Moderator
Korean J Radiol
. 2026 Feb;27(2):174-185.
doi: 10.3348/kjr.2025.1272.
Long-Term Pulmonary Function and Radiologic Abnormalities Up to 3 Years After COVID-19: A Systematic Review and Meta-Analysis
Jiyoung Song[SUP] #[/SUP][SUP] 1 [/SUP], Jong Hyuk Lee[SUP] #[/SUP][SUP] 1 [/SUP], Hyungin Park[SUP] 2 [/SUP], Myoung-Jin Jang[SUP] 3 [/SUP], Soon Ho Yoon[SUP] 1 4 [/SUP]
Affiliations
Objective: To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors.
Materials and methods: A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings.
Results: In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%-40% (P = 0.14). The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%-47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts.
Conclusion: DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.
Keywords: COVID-19; Post-acute COVID-19 syndrome; Pulmonary fibrosis; Pulmonary function tests; Tomography, X-ray computed.
. 2026 Feb;27(2):174-185.
doi: 10.3348/kjr.2025.1272.
Long-Term Pulmonary Function and Radiologic Abnormalities Up to 3 Years After COVID-19: A Systematic Review and Meta-Analysis
Jiyoung Song[SUP] #[/SUP][SUP] 1 [/SUP], Jong Hyuk Lee[SUP] #[/SUP][SUP] 1 [/SUP], Hyungin Park[SUP] 2 [/SUP], Myoung-Jin Jang[SUP] 3 [/SUP], Soon Ho Yoon[SUP] 1 4 [/SUP]
Affiliations
- PMID: 41592552
- DOI: 10.3348/kjr.2025.1272
Objective: To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors.
Materials and methods: A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings.
Results: In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%-40% (P = 0.14). The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%-47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts.
Conclusion: DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.
Keywords: COVID-19; Post-acute COVID-19 syndrome; Pulmonary fibrosis; Pulmonary function tests; Tomography, X-ray computed.