To compare mortality between de-escalation and continued empirical treatment in patients with community-acquired pneumonia.

Using a nationwide administrative database, we identified adult patients with community-acquired pneumonia caused by Streptococcus pneumoniae, other streptococci, Haemophilus influenzae, Klebsiella pneumoniae, or Escherichia coli (n = 10,231) or of unknown etiology (n = 8247), discharged between July 2010 and March 2013. De-escalation was determined by the spectrum and number of antimicrobials at day 4. We used propensity score matching to obtain 489 pairs of de-escalation and continuation groups among pathogen-identified patients and 278 pairs among culture-negative patients to compare mortalities.

In the pathogen-identified patients, de-escalation was noninferior to continuation in 15-day mortality [5.3% in de-escalation versus 4.3% in continuation, a difference of 1.0% (95% confidence interval, −1.7% to 3.7%)] and in-hospital mortality [8.0% in de-escalation versus 8.8% in continuation, a difference of −0.8% (95% confidence interval, −4.3% to 2.7%)]. In the culture-negative cases, de-escalation was noninferior to continuation in terms of 15-day mortality but not in terms of in-hospital mortality.

Among patients with community-acquired pneumonia of specific etiology, de-escalation was noninferior to continuation of empirical treatment, suggesting that de-escalation is a safe strategy and supporting current recommendations. Safety of de-escalation in culture-negative cases is questionable.