Early administration of the first antimicrobials should be considered a marker of optimal care of patients with community-acquired pneumonia rather than a predictor of outcomes

Background: The effect of time of the first antimicrobial dose (TFAD) on the outcomes of community-acquired pneumonia (CAP) remains a controversy. Methods: This was an observational, retrospective study of consecutive adult patients hospitalized with CAP. TFAD was defined as the time in hours from arrival at the emergency department to the intravenous infusion of antimicrobial. All patients received appropriate antibiotic therapy according to available Infectious Diseases Society of America/American Thoracic Society guidelines during the time of our study. Multivariable analysis and a propensity score adjusted methodology were used to measure the association of TFAD with mortality, time to clinical stability (TCS), and length of stay in the hospital (LOS). Results: Data of 372 patients with CAP were studied. A total 29 (8.4%) patients died within 30 days of hospitalization. Our propensity-adjusted logistic regression model did not show a significant association between TFAD and mortality (p= 0.148). Patients who died received antimicrobials significantly earlier than survivors: 5.7. h vs. 7.5. h, respectively (p= 0.04). The LOS and TCS were not significantly affected by the TFAD; the LOS hazard ratio was 0.996 (95% confidence interval 0.97-1.02; p= 0.774) and the TCS hazard ratio was 1.01 (95% confidence interval 0.98-1.03; p= 0.604). Conclusions: TFAD does not seem to be associated with the clinical outcome of patients with CAP. Early TFAD should be considered as an important marker of optimal care of patients with CAP rather than as a factor predicting outcomes.