The evolution of healthcare-associated infection as a concept attests to the need for clinicians to recognize the proliferation healthcare delivery, as many of the traditionally hospital-based interventions now transpire in the ambulatory arena. Healthcare-associated pneumonia (HCAP) is a separate entity in the spectrum of pneumonia. Because of its emerging importance and widely differing pathogen make-up and outcomes in some recent studies, we examined in detail the 5 cohort studies published to date in HCAP to identify the potential reasons for these disparate findings and to identify current knowledge gaps.
We conducted a qualitative review of literature with a pooled unadjusted mortality analysis.
Differences in case definition were the likely reason for disparate microbiology and outcomes. Compared to community-acquired pneumonia (CAP), HCAP patients have consistently higher severity of illness, a higher risk of infection with resistant pathogens, and are more likely to be treated with inappropriate empiric therapy, which increases their mortality risk > 2-fold. In a pooled analysis, where no inter-study statistical heterogeneity was identified, the crude relative risk of mortality in HCAP vs. CAP was 2.16, (95% confidence interval 1.86 to 2.51). Limiting this analysis to the two prospective studies resulted in the pooled relative risk of death of 2.51 (95% confidence interval 1.58 to 3.96) for HCAP vs. CAP. Broad knowledge gaps remain, including the validity of the HCAP definition and the value of guideline-concordant therapy.
HCAP is an important emerging syndrome, and a systematic approach to its study is critical. As evidence in this area builds, it is important to set the research agenda to fill knowledge gaps.
To optimize outcomes, clinicians must recognize risk factors for resistant pathogens in patients presenting with pneumonia from the community. HCAP definition may help tailor appropriate empiric antimicrobial therapy.
Marya Zilberberg, Grant monies (from industry related sources) Research grant from Ortho-McNeil Janssen; Shareholder Shareholder in Johnson&Johnson; No Product/Research Disclosure Information