Prognostic factors in patients hospitalized with community-acquired aspiration pneumonia

Introduction: Patients with aspiration pneumonia (AP) exhibit higher mortality than those with non-AP. However, data regarding predictors of short-term prognosis in patients with community-acquired AP are limited.

Methods: Patients hospitalized with community-acquired pneumonia (CAP) were retrospectively classified into aspiration pneumonia (AP) and non-AP groups. The AP patients were further divided into nonsurvivors and survivors by 30-day mortality, and various clinical variables were compared between the groups.

Results: Of 1249 CAP patients, 254 (20.3%) were classified into the AP group, of whom 76 patients (29.9%) died within 30 days. CURB-65, pneumonia severity index (PSI), and Infectious Diseases Society of America/American Thoracic Society criteria for severe CAP (SCAP) showed only modest prognostic performance for the prediction of 30-day mortality (c-statistics, 0.635, 0.647, and 0.681, respectively). Along with the PSI and SCAP, Eastern Cooperative Oncology Group performance status (ECOG-PS) and blood biomarkers, including, N-terminal of prohormone brain natriuretic peptide (NT-proBNP) and albumin, were independent predictors of 30-day mortality. In models based on clinical prediction rules, including CURB-65, PSI, and SCAP, the addition of ECOG-PS further improved their c-statistics compared to the clinical prediction rules alone. In the four combinations based on SCAP, ECOG-PS, and two blood biomarkers (NT-proBNP and albumin), the c-statistics further increased to reach approximately 0.8.

Conclusions: CURB-65, PSI, and SCAP exhibited only modest discriminatory power in predicting the 30-day mortality of patients with community-acquired AP. The addition of performance status and blood biomarkers, including NT-proBNP and albumin, further increased prognostic performance, showing good predictive accuracy in the SCAP-based model.