Influence of comorbidities in long-term survival of chronic obstructive pulmonary disease patients

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality and morbidity around the world, with comorbidities in COPD being common and having a negative effect on survival. We investigate the effects of comorbidities on long-term survival of COPD patients. Methods: The study included patients with COPD who were hospitalized with an exacerbation. The demographic characteristics, hematological and biochemical parameters, pulmonary function test parameters and comorbidities of the patients were obtained from the hospital database and patient records, and the mortality of the patients was assessed at two years. The parameters considered to be related to mortality were analyzed using the Cox regression method. Results: A total of 826 patients with COPD were included in the study, and the rate of patients with at least one comorbidity was 84.5%. The most common comorbidities were hypertension (n=394, 47.7%), heart failure (n=244, 29.5%) and DM (n=173, 20.9%). In a Cox regression analysis, the Charlson Comorbidity Index was strongly associated with mortality (P=0.000). In Kaplan-Meier analysis, a significant association was noted between the increasing number of comorbidities and long-term mortality, when compared to the patients without comorbidity (comorbidity numbers 1, 2 and >= 3; HR: 1.37, P=0.032, HR: 1.40, P=0.028 and HR: 1.65, P=0.000, respectively). Conclusions: Increasing number of comorbidities in COPD patients with severe exacerbation were found to negatively affect long-term survival. We consider both the evaluation and treatment of comorbidities to be important in the reduction of long-term mortality in patients with COPD.