Economic Burden of COPD by Disease Severity – A Nationwide Cohort Study in Denmark

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) carries a considerable economic burden, both for individuals and societies. This study aimed to assess direct and indirect costs associated with COPD, and how costs vary across disease severity. METHODS: This was a nationwide, population-based cohort study utilizing Danish health registries. Patients; ≥40 years of age, with an in- and/or outpatient diagnosis of COPD (ICD-10 J44) in 2008–2016, were identified in the nationwide Danish COPD Registry. Included patients were matched 1:4 to a population-based non-COPD reference population of 196,623 individuals by sex, year of birth, co-habitation status, and municipality. Patients were grouped by disease severity according to different characteristics including GOLD groups A-D, based on moderate (short-term oral corticosteroid use), presence of severe exacerbations (emergency visit or hospitalization) and symptom score. Index was the date of the first outpatient visit with a symptom score registration. The costs were calculated during a 12 months post-index follow-up. RESULTS: In all, 49,826 patients with COPD (mean age 69.2 years, 52% females) were included. Total annual costs, including direct costs, costs for elderly care, and costs for retirement home, were higher for patients with COPD (€28,969) compared with the reference population (€10,6913). In GOLD groups A-D, the total direct costs were A: €8,766, B: €13,060, C: €11,113, and D: €17,749, respectively. A major driver of direct costs was severe exacerbations. The mean costs per moderate and severe exacerbation were €888 and €7,091, respectively, during 28 days of follow-up. The costs for non-COPD-related Health Care Resource Utilization were higher than the COPD-related costs in GOLD groups A-C, but not in GOLD group D. CONCLUSION: In this nationwide real-world study, total direct costs were three-fold higher among patients with COPD compared with the reference population. Severe exacerbations were a major driver of the direct costs. The costs increased with increasing disease severity.