Impact of guideline-consistent therapy on outcome of patients with healthcare-associated and community-acquired pneumonia.

BACKGROUND

A new category of healthcare-associated pneumonia (HCAP) has been added in the most recent American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines, since multidrug-resistant (MDR) pathogens are more common in patients with HCAP than in those with community-acquired pneumonia (CAP). The optimal empirical management of patients with HCAP remains controversial and adherence to guidelines is inconsistent.

METHODS

A retrospective cohort study of 3295 adults admitted for pneumonia in an academic centre of Canada, between 1997 and 2008.

RESULTS

MDR pathogens were more common among patients with HCAP than in those with CAP, but less so than in other studies. Compared with patients with CAP, those with HCAP had a higher all-cause 30 day mortality [68/563 (12%) versus 201/2732 (7%); P < 0.001] and more frequent need for mechanical ventilation [78/563 (14%) versus 276/2732 (10%); P = 0.01]. In patients with CAP, mortality was lower when treatment was concordant with guidelines [86/1557 (6%) versus 109/1097 (10%) if discordant; adjusted odds ratio 0.6 (0.4-0.8); P < 0.001]. In HCAP, mortality was similar whether or not empirical treatment was concordant with guidelines [6/35 (17%) versus 18/148 (12%) if discordant; P = 0.4]. However, 30 day mortality tended to be higher when the empirical treatment was microbiologically ineffective [4/22 (18%) versus 17/187 (9%) when effective; P = 0.3].

CONCLUSIONS

HCAP is associated with worse outcomes than CAP. MDR pathogens were implicated in only a small fraction of HCAP cases. In our study, unlike CAP, non-respect of current HCAP guidelines had no adverse effect on the ultimate outcome. Strategies for the empirical management of HCAP should be tailored to the local epidemiological context.