The following is the summary of “Effect of positive microbiological testing on antibiotic de-escalation and outcomes in community-acquired pneumonia: a propensity score analysis” published in the December 2022 issue of Clinical microbiology and infections by Alonso, et al.

Community-acquired pneumonia (CAP) patients who are hospitalized continue to be a source of controversy over the efficacy of routine microbiological tests in rationalizing antibiotic use. Researchers hope to learn how the de-escalation of antibiotic treatment and clinical outcomes change after a positive microbiological test for CAP. Adults who were not immunosuppressed hospitalized with CAP were the subjects of a retrospective study. Antimicrobial de-escalation was the primary endpoint of the trial. The 30-day case fatality rate, the incidence of adverse events, and the recurrence of CAP were secondary outcomes. Inverse probability weighting propensity score, logistic regression, and a cause-specific Cox model were used to control for potential confounding factors.

 About 1924 (52.30%) of 3677 CAP patients reported positive microbiological tests. Only 179 out of 1753 (10.2%) patients with negative microbiological test results and 648 (1924) patients with positive test results underwent antimicrobial de-escalation. Positive microbiological testing (adjusted OR [AOR], 2.59; 1.96-3.41) and clinical stability at day 3 (AOR [AOR], 1.87; 1.45-2.10) were the key factors independently linked with antibiotic de-escalation when propensity score was added into the multivariate analysis. An adjusted cause-specific Cox model found no association between antimicrobial de-escalation and an increase in the 30-day case-fatality rate, adverse events, or the recurrence of CAP. 

The AHR for 30-day case-fatality was 0.44 (95% CI, 0.14-1.43), and the AHR for the occurrence of adverse events was 0.77 (95% CI, 0.53-1.12). Hospitalized patients with CAP who had positive microbiological testing were more likely to undergo antimicrobial de-escalation compared to those with negative results, and this did not negatively impact clinically-important outcomes.

Source: sciencedirect.com/science/article/pii/S1198743X22003354