Is chronic obstructive pulmonary disease a risk factor for death in patients with community acquired pneumonia?

Background: It is still a matter of debate whether the outcome of community acquired pneumonia is more severe in patients with chronic obstructive pulmonary disease. We aimed to determine whether chronic obstructive pulmonary disease was associated with increased mortality and to identify risk-factors for mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease.Methods: Retrospective cohort study comparing patients with community acquired pneumonia and chronic obstructive pulmonary disease to patients without chronic obstructive pulmonary disease. We included 1309 patients with community acquired pneumonia admitted from 2011 until 2012 (243 patients with chronic obstructive pulmonary disease and 1066 without chronic obstructive pulmonary disease).Results: At admission patients with community acquired pneumonia and chronic obstructive pulmonary disease presented with more severe pneumonia as measured by CURB-65 score compared to patients without chronic obstructive pulmonary disease. Mortality on day 30 was generally high, and higher among patients with community acquired pneumonia and chronic obstructive pulmonary disease compared to those without chronic obstructive pulmonary disease (16.0% versus 11.3%, p=.04). In an adjusted analysis, however, chronic obstructive pulmonary disease was not independently associated with 30-d mortality (odds ratio 0.94, confidence interval 95% 0.59-1.50). Factors related to mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease were age, premorbid condition, severity of pneumonia as determined by CURB-65 score, and pleural effusion and multi-lobular infiltrate on chest X-ray.Conclusions: Chronic obstructive pulmonary disease was not independently associated with 30-d mortality in patients with community acquired pneumonia.