Heart and cardiovascular comorbidities considerably increase health care use in Danish COPD patients

Background: Patients who share the same comorbidity profile are usually similar in regards to their disease severity, clinical outcomes and treatments, thus identification of comorbidity cluster bears prognostic information. The objective of this study was to identify and characterize comorbidity clusters in Danish COPD patients. Methods: The Danish national register data was used. The study population included all individuals aged 16 years and older who lived in the Danish Capital Region on January 1st 2012, who were diagnosed with the COPD (N = 70.274). Selected chronic conditions were identified using diagnostic algorithms. A Two Step Cluster Analysis was performed. Results: Eighty one percent of the COPD population had chronic comorbidities; the most common was hypertension (47.6%), and the least common was anxiety (0.1%). Three comorbidity clusters were identified. Cluster 1 contained 16% of COPD population where everybody had a heart and/or cardiovascular condition together with the remaining comorbidities. Cluster 2 contained 30% of COPD population where appr. 1/3 suffered from allergies, while the rest had no comorbidities. Cluster 3 contained 54% of COPD population where all but heart and cardiovascular comorbidities were common. Cluster 1 had the highest proportion of individuals over 65 years, as well as individuals with the lowest education. After adjusting for sociodemographic characteristics, Cluster 1 had the highest number of hospitalizations and bed days and Cluster 3 had the highest numbers of specialist visits. Conclusions: Procedures to address comorbidities in COPD patient care should be developed to decrease hospitalization rates. A special attention should be payed to heart and cardiovascular comorbidities. Key messages: 80% COPD patients have comorbidities. COPD patients with heart and cardiovascular comorbidities represent the most socioeconomically vulnerable and most often hospitalized COPD patient subpopulation.