Age-, sex-, and smoking-specific prevalence and progression in interstitial lung abnormality: patient-level meta-analysis

Year: 2026

Type: article

Study designs: Systematic Review, Meta-Analysis

Abstract: RATIONALE: Interstitial lung abnormalities (ILAs) are incidental computed tomography (CT) findings that often represent early, subclinical interstitial lung disease. Their prevalence and progression rates vary widely across studies, emphasizing the need to understand the impact of age, sex, and smoking for better risk stratification and management. OBJECTIVES: To evaluate the prevalence and progression rates of ILA by age, sex, and smoking intensity using individual patient-level data from global cohorts, and to analyze progression-free survival (PFS). METHODS: Systematic searches in OVID-MEDLINE and Embase identified eligible original articles reporting ILA prevalence or progression, confirmed through radiologist-reviewed CT scans. Random-effects models were used to pool estimates stratified by age, sex, and smoking intensity. Risk of bias was assessed using the Newcastle-Ottawa Scale. PFS probabilities were calculated using Kaplan-Meier analysis. RESULTS: Data from 14 studies comprising 31 739 individual subjects showed a pooled ILA prevalence of 5.6% (95% CI, 4.3%-7.3%), increasing with age from 2.5% (<55 years) to 14.6% (≥80 years). Age was the most influential factor, and it was further amplified in males and individuals with >30 pack-years. The overall pooled progression was 34%, with fibrotic ILAs exhibiting higher progression, and age did not affect progression. PFS was evaluated in 202 individuals with ILA, with estimated rates of 76% at 3 years and 55% at 5 years. CONCLUSIONS: Age is the strongest determinant of ILA prevalence. ILAs show significant progression on imaging over time, and progression is mainly driven by fibrotic features rather than age once ILA is established. Given the higher prevalence in older adults, targeted screening in aging populations remains appropriate, while follow-up strategies should be guided by fibrotic burden rather than age.

Source: Annals of the American Thoracic Society

DOI: 10.1093/annalsats/aaoag071

Institutions: Jeonbuk National University Hospital, Jeonbuk National University, Seoul National University Hospital, Brigham and Women's Hospital, Weill Cornell Medicine, Columbia University Irving Medical Center, Columbia University, Asan Medical Center, Pusan National University Yangsan Hospital, Pusan National University, University of Ulsan, Ulsan University Hospital, Prince Charles Hospital, University of Manchester, Manchester University NHS Foundation Trust, Wythenshawe Hospital, University of Parma, Fondazione IRCCS Istituto Nazionale dei Tumori, Instituto Nacional de Enfermedades Respiratorias, Tufts University, Lahey Hospital and Medical Center, Lahey Medical Center, Royal Brompton & Harefield NHS Foundation Trust, Harefield Hospital, Royal Brompton Hospital, Imperial College London, King's College London, University of Calgary, Harvard University, Seoul National University, National Jewish Health

Language: English

Topic: Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis

Subfield: Pulmonary and Respiratory Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Research Foundation of Korea, National Institutes of Health, National Heart, Lung, and Blood Institute, National Center for Advancing Translational Sciences

OpenAlex ID: W7140123569