Microbiology Comment Nudge Improves Pneumonia Prescribing

BACKGROUND: Systematic and behavioral interventions are needed to improve antibiotic use for common conditions like pneumonia. METHODS: Single pretest, post-test quasi-experiment in a 4-hospital health system in metropolitan Detroit, Michigan. Hospitalized patients treated with anti-methicillin-resistant Staphylococcus aureus and antipseudomonal antibiotics for respiratory infections from August 1, 2015, through January 31, 2016, and August 1, 2016, through January 31, 2017, were eligible for inclusion. Beginning in May 2016, respiratory cultures with no dominant organism growth and no Pseudomonas sp. or Staphylococcus aureus were reported by the clinical microbiology laboratory as “commensal respiratory flora only: No S. aureus/MRSA [methicillin-resistant Staphylococcus aureus] or P. [Pseudomonas] aeruginosa.” Before intervention, these were reported as “commensal respiratory flora.” The primary end point was de-escalation or discontinuation of anti-methicillin-resistant Staphylococcus aureus or antipseudomonal therapy. Secondary clinical and safety outcomes included nephrotoxicity and in-hospital, all-cause mortality. RESULTS: Two hundred ten patients were included in the study. De-escalation/discontinuation was more commonly performed in the intervention group (39% vs 73%, P < .001). After adjusting for APACHE II and Charlson Comorbidity Index, the intervention comment was associated with a 5.5-fold increased odds of de-escalation (adjusted odds ratio, 5.5; 95% confidence interval, 2.8–10.7). Acute kidney injury was reduced in the intervention phase (31% vs 14%, P = .003). No difference in all-cause mortality was detected between the groups (30% vs 18%, P = .052). CONCLUSION: A simple, behavioral nudge in microbiology reporting increased de-escalation and discontinuation of unnecessary broad-spectrum antibiotics. This highlights the importance of clear, persuasive communication of diagnostic testing in improving antibiotic prescribing behaviors.