Risk Factors Associated with a First Exacerbation Among Patients with COPD Classified as GOLD A and B in Routine Clinical Practice in the UK

Purpose: Risk factors for exacerbations of chronic obstructive pulmonary disease (COPD) have been previously characterized for patients with more severe cases of COPD. It is unclear how the risk of first exacerbation may best be identified in patients with less severe disease. This study investigated risk factors for first exacerbation among English patients with COPD classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) group A or B. Patients and Methods: A retrospective cohort study using data from the UK Clinical Practice Research Datalink (CPRD) AURUM linked to Hospital Episode Statistics. Patients with COPD aged >= 35 years and classified as GOLD group A or B (2020 criteria) from January 2013-December 2019 were eligible. Patients were required to have 24 months history in CPRD (baseline). Two cohorts were defined: cohort 1 included patients with no severe exacerbations during baseline; cohort 2 included patients with no moderate or severe exacerbations during baseline. Risk factors associated with severe, or combined moderate and severe exacerbation were examined for up to 5 years of follow-up. Results: Overall, 194,948 patients were included in cohort 1 (mean age 66.2 years; 55.2% male), and 148,396 patients in cohort 2 (mean age 66.1 years; 56.6% male). Identified risk factors for exacerbation (and associated 1-year absolute risk of severe, or combined moderate and severe exacerbation, respectively) included: Medical Research Council dyspnea scale score (15.9%/28.4%); COPD Assessment Test score (9.6%/25.3%); GOLD grade of airflow limitation (forced expiratory volume in 1 second % predicted; 13.6%/27.5%); and lung cancer (8.1%/23.6%). After adjustment for risk factors, these factors remained independently associated with severe exacerbation at 1, 3, and 5 years of follow-up. Conclusion: The identified risk factors may aid physicians in the early recognition of patients with COPD classified as GOLD group A or B at risk of first exacerbation.