The goal of this observational study is to learn about the comorbidity patterns of interstitial and airway abnormalities in adults undergoing health examinations in China. The main questions it aims to answer are:

How do early interstitial lung abnormalities progress to comorbid interstitial and airway diseases? What are the key factors associated with this progression?

Participants undergoing routine health examinations will be assessed for interstitial and airway abnormalities based on imaging and clinical data. Longitudinal follow-up will be used to evaluate disease progression and identify associated risk factors.

Inclusion Criteria:

• Underwent chest CT examination between January 1, 2017 and December 31, 2024
• Age 18 years or older at the time of examination

Exclusion Criteria:

- Missing or incomplete key demographic or imaging information (e.g., missing date of examination, sex, age, or CT report)

Participants were recruited from multiple health checkup centers across various regions of China between 2017 and 2024. Specifically, this retrospective study included data from 10 hospital-based health examination institutions located within the four major economic regions of China (East, Central, West, and Northeast). All available health examination records of individuals who underwent chest CT scans during this period were collected for analysis.