Impact of Comorbid Interstitial Lung Abnormalities on Acute Exacerbations of COPD: A Hospital-Based Retrospective Cohort Study

OBJECTIVE: To assess the influence of comorbid interstitial lung abnormalities (ILA), lung fibrosis (LF), and interstitial lung disease (ILD) on clinical characteristics and in-hospital outcomes in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). METHODS: In this retrospective cohort study, AECOPD patients were stratified by ILA, LF, or ILD status. Multivariable regression analyzed associations with outcomes, including in-hospital mortality, ICU admission, ventilation use, 30-day readmission, and length of stay (LOS). Subgroup and sensitivity analyses assessed robustness. RESULTS: Among 11,457 AECOPD patients, 33.1% had ILA, 25.9% had LF, and 5.0% had ILD. After multivariable adjustment for potential confounders, the presence of ILA, LF, or ILD was not independently associated with in-hospital mortality (ILA: aOR 0.93, 95% CI 0.75-1.14; LF: aOR 0.87, 95% CI 0.70-1.10; ILD: aOR 1.04, 95% CI 0.70-1.53). All conditions significantly increased ICU admission and noninvasive ventilation use but reduced invasive ventilation use. CONCLUSIONS: While not independent mortality predictors, ILA/LF/ILD signify greater disease severity and resource utilization during AECOPD, evidenced by higher ICU needs yet paradoxically lower invasive ventilation, a pattern that might be attributed to distinct pathophysiology and clinical management goals in this complex subgroup. This underscores clinical heterogeneity and necessitates tailored management and goals-of-care discussions for this high-risk subgroup.