Health-care-associated pneumonia (HCAP) is a relatively new concept. Epidemiologic
studies are limited, and initial empirical antibiotic treatment is still under discussion.
This study aimed to reveal the differences in mortality and pathogens between HCAP
and community-acquired pneumonia (CAP) in each severity class, and to clarify the
strategy for the treatment of HCAP.
We conducted a retrospective observational study of patients with HCAP and CAP who
were hospitalized between November 2005 and January 2007, and compared baseline characteristics,
severity, pathogen distribution, antibiotic regimens, and outcomes. In each severity
class (mild, moderate, and severe) assessed using the A-DROP scoring system (ie, age,
dehydration, respiratory failure, orientation disturbance, and low BP), we investigated
the in-hospital mortality and occurrence of potentially drug-resistant (PDR) pathogens.
A total of 371 patients (141 HCAP patients, 230 CAP patients) were evaluated. The
proportion of patients in the severe class was higher in the HCAP patients than in
CAP patients. In the moderate class, the in-hospital mortality proportion of HCAP
patients was significantly higher than that of CAP patients (11.1% vs 1.9%, respectively;
p = 0.008). In moderate-class patients in whom pathogens were identified, PDR pathogens
were isolated more frequently from HCAP patients than from CAP patients (22.2% vs
1.9%, respectively; p = 0.002). The occurrence of PDR pathogens was associated with
initial treatment failure and inappropriate initial antibiotic treatment.
The present study provides additional evidence that HCAP should be distinguished from
CAP, and suggests that the therapeutic strategy for HCAP in the moderate class holds
the key to improving mortality. Physicians may need to consider PDR pathogens in selecting
the initial empirical antibiotic treatment of HCAP.