Hospitalization due to community-acquired pneumonia in patients with chronic obstructive pulmonary disease: incidence, epidemiology and outcomes

Abstract

Objectives: Community-acquired pneumonia (CAP) is an important complication in patients with chronic obstructive pulmonary disease (COPD). This study aimed to define incidence, and outcomes of COPD patients hospitalized with pneumonia in the city of Louisville, and to estimate the burden of disease in the US population.

Methods: This was a secondary analysis of a prospective population-based cohort study of residents in Louisville, Kentucky, 40 years old and older, from 1 June 2014 to 31 May 2016. All adults hospitalized with CAP were enrolled. The annual incidence of pneumonia in COPD patients in Louisville was calculated and the total number of adults with COPD hospitalized in the United States was estimated. Clinical outcomes included time to clinical stability (TCS), length of hospital stay (LOS) and mortality.

Results: From a Louisville population of 18 246 patients with COPD, 3419 pneumonia hospitalizations were documented during the 2-year study. The annual incidence was 9369 patients with pneumonia per 100 000 COPD population, corresponding to an estimated 506 953 adults with COPD hospitalized due to pneumonia in the United States. The incidence of CAP in patients without COPD was 509 (95% CI 485-533) per 100 000. COPD patients had a median (interquartile range) TCS and LOS of 2 (1-4) and 5 (3-9) days respectively. The mortality of COPD patients during hospitalization, at 30 days, 6 months and 1 year was 193 of 3419 (5.6%), 400 of 3374 (11.9%), 816 of 3363 (24.3%) and 1104 of 3349 (33.0%), respectively.

Conclusions: There was an annual incidence of 9369 cases of hospitalized CAP per 100 000 COPD patients in the city of Louisville. This was an approximately 18-fold greater incidence of CAP in COPD patients than in those without COPD.

Keywords: COPD; Epidemiology; Incidence; Mortality; Pneumonia.