Guideline-concordant antibiotic therapy for the hospital treatment of community-acquired pneumonia and 1-year all-cause and cardiovascular mortality in elderly patients surviving to discharge

Background — Selection of empiric antibiotic treatment for community-acquired pneumonia (CAP) that is concordant with clinical practice guidelines has been associated with improved short-term outcomes of this infection, but whether it is also associated with longer-term outcomes is unknown.

Research Question — Is guideline-concordance of the initial antibiotic treatment given to elderly patients hospitalized with CAP associated with the 1-year all-cause and cardiovascular mortality risk of those patients that survive hospitalization for this infection?

Study Design and Methods — We identified 1909 elderly (>65 years of age) patients that survived hospitalization for CAP at The Ottawa Hospital in Ontario, Canada between 2004 and 2015. Linking patients’ information to hospital and provincial datasets, we analyzed whether the selection of the initial antibiotic therapy for their CAP was concordant with current clinical practice guidelines, and whether guideline-concordance was associated with 1-year all-cause and cardiovascular mortality after their index CAP hospitalization while adjusting for their overall 1-year expected death risk, CAP severity, and history of previous pneumonia admissions, myocardial infarction, heart failure or cerebrovascular disease.

Results — Selection of guideline-concordant antibiotic therapy was associated with a trend towards lower all-cause mortality at 1-year post-CAP (hazard ratio [HR] 0.82, 95%CI 0.65-1.04, p=0.099). Furthermore, the use of guideline-concordant antibiotic therapy was associated with a significant almost 50% reduction in cardiovascular death risk 1 year after CAP admission (HR 0.53, 95%CI 0.34-0.80, p=0.003).

Interpretation — Use of guideline-concordant antibiotic therapy for CAP treatment in elderly hospitalized patients is associated with a significant reduction in the risk of cardiovascular death at 1-year post-CAP. This finding further supports current clinical practice guideline recommendations for CAP treatment.