Abstract
OBJECTIVE: Pre-chronic obstructive pulmonary disease (Pre-COPD) refers to individuals who do not meet traditional diagnostic criteria for COPD but already show respiratory symptoms, abnormal lung function, or imaging changes. The purpose of this study was to complete a systematic review and meta‑analysis of the incidence and risk factors for progression from pre‑COPD to COPD. METHODS: We searched ten databases through December 31, 2024. The Newcastle-Ottawa Scale (NOS) was applied to assess the methodological quality of the eligible studies. We extracted incidence to quantify progression from pre-COPD to COPD and odds ratios (ORs) and hazard ratios (HRs) with their 95% confidence intervals (CIs) to identify associated risk factors. Effect sizes were pooled using fixed-effects and random-effects models. RESULTS: Among 5289 articles, 21 were eligible, and 13 reported incidence. The pooled incidence of progression from pre-COPD to COPD was 20% (n = 13, 95% CI 15-26%). We identified five statistically significant factors linked to clinical development in pre-COPD: preserved ratio impaired spirometry (PRISm) (ORs=2.92, 95% CI 1.79-4.74), age (ORs=1.09, 95% CI 1.03-1.15), smoking history (ORs=4.08, 95% CI 2.14-7.18, HRs=2.21, 95% CI 1.59-3.07), non-obstructive chronic bronchitis (NOCB) (ORs=2.07, 95% CI 1.32-3.24, HRs=2.46, 95% CI 1.61-3.75), and asthma (ORs=2.50, 95% CI 1.93-3.24). CONCLUSION: This meta-analysis indicates a high incidence of progression from pre-COPD to COPD. Moreover, age, smoking history, NOCB, PRISm, and asthma were significantly associated with an increased risk of clinical progression in individuals with pre-COPD. Integrating these risk factors into clinical risk-stratification tools and follow-up strategies may help clinicians identify high-risk individuals with pre-COPD, facilitating enhanced surveillance, targeted smoking cessation interventions, optimized asthma management, and other preventive interventions to delay or prevent COPD onset.