Mortality in healthcare-associated pneumonia in a low resistance setting: a prospective observational study

Abstract

Background: The classification of pneumonia as community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) has implications for selection of initial antimicrobial therapy. HCAP has been associated with an increased prevalence of multidrug-resistant (MDR) pathogens and with high mortality leading to recommendations for broad empiric therapy. Methods: We performed a prospective, population-based study on consecutive adults (≥ 18 years) admitted for pneumonia over 1 calendar year. Patients were classified by pneumonia type and severity. Microbial etiologic testing was performed on all patients. Treatment, length of stay, and mortality rates were compared. Results: A total of 373 admissions were included, 94% of all eligible patients. They were classified as CAP (n = 236, 63%) or HCAP (n = 137, 37%). Chronic underlying disease was more commonly found among patients with HCAP compared with CAP (74% vs 51%, p < 0.001). Mycoplasma pneumoniae was more common among CAP patients (p < 0.01), while gram-negative bacteria were more often found among HCAP patients (p = 0.02). No MDR pathogens were detected, and rates of Staphylococcus aureus were similar in the two groups. HCAP patients were not more likely to receive ineffective initial antimicrobial therapy. HCAP patients had worse prognostic scores on admission and higher in-house mortality than CAP patients (10% vs 1%, respectively, p < 0.01). Conclusions: Even in a low resistance setting, patients with HCAP have increased mortality compared with patients with CAP. This is most likely explained by a higher prevalence of co-morbidities. Our data do not support broad-spectrum empiric antibiotic therapy for HCAP.

Keywords::

• Healthcare-associated pneumonia
• community-acquired pneumonia
• antimicrobial resistance
• etiology
• mortality

Acknowledgments

The authors wish to thank Janus F. Gudnason MD, Kristinn L. Hallgrimsson MD, Berglind Kristjansdottir MD, and Gunnsteinn Haraldsson PhD for their work in recruiting participants and processing clinical samples. We wish to thank the house staff, nurses, and laboratory personnel of Landspitali University Hospital for their assistance in recruiting participants and collecting and preserving samples.

Declaration of interest: This work was supported by grants from the Icelandic Center for Research, Rannís (grant no. 100436021), URL: http://rannis.is/english/home/, the Landspitali University Hospital Science Fund, and the University of Iceland Research Fund.