Influence of comorbidities on hospital mortality and healthcare utilization in hospitalized chronic obstructive pulmonary disease patients

Background: Comorbidities of chronic obstructive pulmonary disease (COPD) are associated with both increased short-term and long-term mortality. However, information on regarding the influence of comorbidities on hospital mortality and healthcare utilization remain limited. Objective: To evaluate the influence of COPD and comorbidities associated with increased risk of hospital mortality and healthcare utilization. Materials and Methods: A retrospective cohort study was performed on COPD patients admitted to the Chiang Mai University Hospital between 2007 and 2013. Logistic regression was performed to identify independent comorbidities that increased the risk of hospital mortality and influenced healthcare utilization. Results: The present study involved 739 COPD patients with 1,099 visits. The hospital mortality rate was 12.3%. The comorbidities associated with increased hospital mortality were depression (odds ratio [OR] 8.61, 95% confidence interval [CI] 1.66 to 43.95, p=0.010), atrial fibrillation (OR 2.37, 95% CI 1.33 to 4.21, p=0.003), and coronary artery disease (OR 1.85, 95% CI 1.03 to 3.32, p=0.04). The comorbidities were also associated with increased hospital length of stay [7 (3 to 12) versus 5 (3 to 8) days, p=0.001], mechanical ventilation days [5 (2 to 13) versus 3 (2 to 6) days, p=0.029], and total hospital costs [915.1 (401.2 to 2,258.4) versus 562.1 (338.1 to 1,372.9) USD, p=0.010]. In addition, comorbidities were associated with increased hospital mortality (one and two comorbidities: OR 2.06, 95% CI 1.24 to 3.43, p=0.005 and OR 5.47, 95% CI 2.07 to 14.47, p=0.001, respectively). Conclusion: The COPD comorbidities, which are depression, atrial fibrillation, and coronary artery disease, were associated with increased hospital mortality and healthcare utilization.