Association between chronic obstructive pulmonary disease and 28-day mortality in patients with sepsis: a retrospective study based on the MIMIC-III database

Abstract Background : Along with a variety of chronic co-morbid medical conditions, sepsis is a common cause of mortality in critically ill patients, and chronic obstructive pulmonary disease (COPD) is one of the most common comorbidities in septic patients. However, the impact of COPD on patients with sepsis is still unclear. Therefore, the purpose of this study was aimed to assess the effect of COPD on the prognosis of sepsis patients based on MIMIC-III database. Methods : In this retrospective study based on the Medical Information Mart for Intensive Care (MIMIC)-III database version 1.4 (v1.4), we collected clinical data and 28-day all-cause mortality from sepsis patients in intensive care unit (ICU) who met the diagnostic criteria of Sepsis 3 on ICU admission between 2008 and 2012. ICD-9 code was used to identified COPD. We applied Kaplan-Meier analysis to compare difference between 28-day all-cause mortality of COPD and non-COPD patients. Univariate and multivariate cox proportional-hazards model was applied to explore the risk factor associated with 28-day all-cause mortality in patients with sepsis. Results : 6257 patients with sepsis were included in this study, including 955 (15.3%) with COPD and 5302 without COPD (84.7%). Compared with sepsis patients without COPD, sepsis patients with COPD were older (median: 73.5 vs 65.8, P<0.001), had a higher simplified acute physiology score II (SAPSII) (median: 40.0 vs 38.0, P<0.001) and greater proportion of mechanical ventilatory support (MV) (55.0% vs 48.9%, P=0.001). In our study, patients with COPD had higher 28-day all-cause mortality (23.6% vs 16.4%, P < 0.001) than non-COPD patients. After adjusting the confounding factors, the results showed that COPD was an independent risk factor for the 28-day all-cause mortality in septic patients (HR 1.30, 95%CI: 1.12-1.51, P=0.001). Conclusions : The comorbidity of COPD was an independent predictor of 28-day all-cause mortality in critical septic patients. Clinically, sepsis patients with COPD should be given additional care.