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

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.

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.

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).

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.