PurposeWe aimed to assess the effects of comorbidities on COPD costs and to investigate the relationship between comorbidities and clinical variables.Patients and methodsAll patients hospitalized with a diagnosis of COPD exacerbation between January 1, 2014, and December 31, 2014, at all state hospitals of Aydın province, a city located in the western part of Turkey, were included in this study. The costs examined in the study pertained to medications, laboratory tests, hospital stays, and other treatment-related factors, such as consumption of materials, doctor visits, and consultation fees.ResultsA total of 3,095 patients with 5,237 exacerbations (mean age, 71.9±10.5 years; 2,434 males and 661 females) were evaluated. For 880 of the patients (28.9%), or 3,852 of the exacerbations (73.1%), at least one comorbid disease was recorded. The mean cost of each exacerbation was $808.5±1,586, including $325.1±879.9 (40.7%) for hospital stays, $223.1±1,300.9 (27.6%) for medications, $46.3±49.6 (0.9%) for laboratory expenditures, and $214±1,068 (26.5%) for other treatment-related factors, such as consumption of materials, doctor visits, and consultation fees. The cost of each exacerbation was $1,014.9 in patients with at least one comorbidity, whereas it was $233.6 in patients without comorbidity (P<0.001). Age >65 years, female gender, hospitalization in an intensive care unit, invasive or noninvasive mechanical ventilation, and a long duration of hospitalization were all found to be significant factors in increasing total costs during the exacerbations requiring hospitalization (P<0.05 for all).ConclusionComorbidities have an important role in the total costs of acute exacerbations of COPD. Strategies for the prevention, diagnosis, and effective management of comorbidities would decrease the overall financial burden associated with acute exacerbations of COPD.