Comorbidities in Swedish COPD and non-COPD patients: ARCTIC study

Abstract

Background: Identifying comorbidities in chronic obstructive pulmonary disease (COPD) may lead to improved disease management, survival and costs. Objective: To compare comorbidities and associated healthcare use between COPD and non-COPD patients. Methods: COPD patients9 medical records data from primary care in Sweden were linked to primary and secondary care national registries information. Data included prescriptions, mortality, income/social characteristics, and pre- and post-COPD diagnosis comorbidities. Comorbidity prevalence was compared between COPD patients and an age-, gender- and calendar year-matched reference population. Healthcare costs were categorized as COPD- and non-COPD related, and comprised drug costs and primary and secondary care visits. Results: There were 17,545 COPD and 84,514 reference group patients. A higher pre-COPD diagnosis comorbidity of asthma (10.1% vs 5.6%), depression (5.0% vs 2.8%), type II diabetes (5.6% vs 3.8%), osteoporosis (1.3% vs 0.7%), fractures (7.5% vs 5.7%), cardiovascular disease (30.2% vs 21.6%), rheumatoid arthritis (1.5% vs 0.9%), and lung cancer (0.4% vs 0.1%) was observed in COPD patients compared with reference patients. Two years post-diagnosis, the comorbidity rate increased for both the COPD and the reference patients, but the proportion of COPD patients with each comorbidity was considerably higher than for the reference patients. Costs of treating COPD comorbidities were higher than COPD-related costs at all time points (e.g. €8,295 vs €620 for non-COPD vs COPD-related hospital nights, respectively, in 2013). Conclusion: Comorbidities are more prevalent in COPD than non-COPD patients and are the major contributor to healthcare costs.