Impact of guideline-concordant antibiotics and macrolide/[beta]-lactam combinations in 3203 patients hospitalized with pneumonia: prospective cohort study

Clin Microbiol Infect 2013; 19: 257-264 For patients hospitalized with pneumonia, guidelines provide empirical antibiotic recommendations and some studies suggest that macrolide/[beta]-lactam combinations are preferable. We hypothesized that guideline-concordant regimens, particularly macrolide/[beta]-lactams, would reduce mortality and ICU admissions. All patients hospitalized with pneumonia in Edmonton, Alberta, Canada, were managed according to a clinical pathway and enrolled in a population-based registry. Clinical data, Pneumonia Severity Index and treatments were collected. Guideline-concordant regimens were macrolides/[beta]-lactams or respiratory fluoroquinolone monotherapy. The main outcome was in-hospital mortality. The study included 3203 patients and most had severe pneumonia (63% PSI Class IV-V). Three hundred and twenty-one (10.0%) patients died, 306 (9.6%) were admitted to the ICU and 570 (17.8%) achieved the composite of death or ICU admission. Most (n = 2506) patients received guideline-concordant antibiotics. Receipt of guideline-concordant antibiotics was not associated with a reduction in mortality alone (231 (9.2%) vs. 90 (12.9%); adjusted odds ratio (aOR), 0.82; 95% CI, 0.61-1.09; p 0.16), but was associated with decreased death or ICU admission (14.7% vs. 29.0%; aOR, 0.44; 95% CI, 0.36-0.54; p