Postoperative pneumonia among patients with and without COPD in Spain from 2001 to 2015

Abstract

Background: To describe and compare incidence, characteristics and outcomes of postoperative pneumonia among patients with or without COPD.

Methods: We included hospitalized patients aged ≥40 years whose medical diagnosis included pneumonia and ventilator-associated pneumonia in the secondary's diagnosis field and who were discharged from Spanish hospitals from 2001 to 2015. Irrespectively of the position at the procedures coding list, we retrieved data about the type of surgical procedures using the enhanced ICD-9-CM codes. We grouped admissions by COPD status. The data were collected from the National Hospital Discharge Database.

Results: We included 117,665 hospitalizations of patients that developed postoperative pneumonia (18.06% of them had COPD). The incidence of postoperative pneumonia was significantly higher in COPD patients than in those without COPD (IRR 1.93, 95%CI 1.68-2.24). In hospital-mortality (IHM) was significantly lower in the first group of patients (29.79% vs 31.43%, p < 0.05). Factors independently associated with IHM, among COPD and non-COPD patients, were older age, more comorbidities, mechanical ventilation, pleural drainage tube, red blood cell transfusion, dialysis and emergency room admission. Time trend analysis showed a significant decrease in IHM from 2001 to 2015. COPD was associated with lower IHM (OR 0.91, 95%CI 0.88-0.95).

Conclusions: The incidence of postoperative pneumonia was higher in COPD patients than in those without this disease. However, IHM was lower among COPD patients. IHM decreased over time, regardless of the existence or not of COPD.

Keywords: COPD; In-hospital mortality; Incidence; Postoperative pneumonia; Trends.