Mortality differences among hospitalized patients with community-acquired pneumonia in three world regions: results from the Community-Acquired Pneumonia Organization (CAPO) International Cohort Study

Abstract

Background: Community-acquired pneumonia (CAP) causes considerable worldwide mortality, but limited data compare the mortality in different regions of the world. Our objective was to determine if there was a difference in mortality among hospitalized patients with CAP in three continental regions of the world.

Methods: This was a cohort study of patients hospitalized for CAP between November 2001 and December 2011 from 70 institutions in 16 countries in US/Canada, Europe and Latin America; the Community-Acquired Pneumonia Organization (CAPO) international database. The primary outcome was mortality, and factors of interest included world region, processes of care, severity of disease, associated pathogen, specific comorbidities, and antimicrobial therapy. Multivariable logistic regression was performed to adjust for confounding effects on differences in mortality between regions. Patients were analyzed separately based on their intensive care unit admission status.

Results: A total of 6371 patients were reviewed. Latin America had the highest mortality (13.3%) followed by Europe (9.1%) and the USA/Canada (7.3%) (P < 0.001 for differences between regions). Important confounding variables included comorbidities (i.e., congestive heart failure, cerebrovascular disease), elevated blood urea nitrogen level, antimicrobial therapy (macrolide or fluoroquinolone use), and whether the patient had prior vaccinations (influenza, pneumococcal). After adjustment for confounding variables, estimated differences in mortality between the three regions were significantly reduced for both patients in the ICU and the ward.

Conclusions: There was an observed discrepancy in CAP mortality between three world regions. Identified factors that contributed to these differences included incidence of H1N1 infection, elevated BUN, cerebrovascular disease, macrolide use, fluoroquinolone use, and vaccinations. Treatment regimen (fluoroquinolone and macrolide use) and preventive measures (vaccinations) were variables that may be modified to help alleviate the differences.