Risk Factors of FEV₁/FVC Decline in COPD Patients

Background: Factors influencing the decline in forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) for chronic obstructive pulmonary disease (COPD) progression remain uncertain. We aimed to identify risk factors associated with rapid FEV1/FVC decline in patients with COPD. Methods: This multi-center observational study was conducted from January 2012 to December 2022. Eligible patients were monitored with symptoms, spirometric tests, and treatment patterns over 3 years. Rapid FEV1/FVC decliners were defined as the quartile of patients exhibiting the highest annualized percentage decline in FEV1/FVC. Results: Among 1,725 patients, 435 exhibited rapid FEV1/FVC decline, with an annual change of −2.5%p (interquartile range, −3.5 to −2.0). Rapid FEV1/FVC decliners exhibited lower body mass index (BMI), higher smoking rates, elevated post-bronchodilator (BD) FEV1, higher post-BD FEV1/FVC, and a lower prevalence of Staging of Airflow Obstruction by Ratio (STAR) stage IV. Rapid FEV1/FVC decline was not linked to the annual exacerbation rate, but there was an association with symptom deterioration and FEV1 decline. In multivariable analyses, low BMI, current smoking, increased modified Medical Research Council dyspnoea score, low post-BD FEV1, low STAR stage, high forced mid-expiratory flow (FEF25-75%), accelerated FEV1 decline, and not initiating dual BD therapy were identified as independent risk factors for rapid FEV1/FVC decline. Conclusion: We identified the risk factors for rapid FEV1/FVC decline, including BMI, smoking, symptoms deterioration, FEV1 decline, and adherence to standard inhaler treatment. Our findings underscore the potential benefits of maintaining consistent use of long-acting beta-agonist/long-acting muscarinic antagonist even in the presence of worsening symptoms, in attenuating FEV1/FVC decline.